5-Deoxy-3-O-arylmethyl or substituted arylmethyl-1, 2-0-alkylidene-alpha-D-xylofuranose herbicide derivatives

ABSTRACT

5-Deoxy-3-0-arylmethyl or substituted arylmethyl-1,2-0-alkylidene-a-D-xylofuranose and 5-C-alkyl and alkenyl derivatives thereof. The compounds are useful as herbicides and plant growth regulators.

BACKGROUND OF THE INVENTION

This invention relates to 5-deoxy, 5-C-alkyl and5-C-alkylidene-5-deoxy-3-O-arylmethyl and substitutedarylmethyl-1,2-O-alkylidene-a-D-xylofuranoses and to application of5-deoxy-3-O-arylmethyl, and substitutedarylmethyl-1,2-O-alkylidene-a-D-xylofuranoses and 5-C-alkyl and5-C-alkenyl derivatives thereof as herbicides and plant growthregulators. The invention also relates to the preparation of suchcompounds.

The laboratory preparation of3-O-benzyl-5-deoxy-1,2-O-isopropylidene-a-D-xylofuranose for the purposeof conducting academic sugar studies is referenced in TetrahedronLetters No. 26, pp. 2447-2448 (1979). The preparation of3-O-benzyl-5-deoxy-1,2-O-isopropylidene-5-C-propyl-a-D-xylofuranose asan intermediate in the multistep synthesis of the antibiotic(-)-Canadensolide is described in Tetrahedron Letters No. 35, pp.3233-3236 (1978) and J. Chem. Soc. Jap., Chem. Ind. Chem. 1981(5),769-755 Chem. Abstracts, Vol. 83, issue 932, (1981), Abstract No.317647. The laboratory preparation of3-O-benzyl-5-deoxy-5-C-methylene-1,2-O-isopropylidene-a-D-xylofuranoserelative to certain academic studies is described in numerouspublications, including Synthesis 636 (1980); Tetrahedron Letters 4841(1979); Carbohydrate Research 48, 143 (1976) Tetrahedron Letters 2623(1975); Helv. Chim Acta 1303 (1973); J. Chem. Soc. Perkin Trans I. 38(1973); Carbohyd. Research 26, 230 (1973); Carbohyd. Research 22, 227(1972); Carbohyd. Research, 215 (1970); J. Amer. Chem. Soc. 78, 2846(1956); Carbohyd. Res. 7, 161 (1968), Methods in Carbohyd. Chem. Vol. VI297 (1972).

The laboratory preparation of3-O-benzyl-5-deoxy-5-C-ethylmethylene-1,2-O-isopropylidene-a-D-xylofuranoseis described in Tetrahedron Letters 3233 (1978) and the laboratorypreparation of3-O-benzyl-5,6-dideoxy-1,2-O-isopropylidene-5-C-methylene-a-D-xylo-hexofuranoseis described in Helvetica Chimica Acta 58, 1501 (1975).

The laboratory preparation of3-O-benzyl-6,7-dideoxy-1,2-O-isopropylidene-a-D-xylo-heptofuranos-5-uloseand/or3-O-benzyl-6-deoxy-1,2-O-isopropylidene-a-D-xylohexofuranos-5-ulose foracademic studies is described in Carbohydrate Research 31 (1973), pages387-396; Carbohydrate Research 29 (1973), pages 311-323; Bulletin of theChemical Society of Japan, 51 (12) (1978), pages 3595-3598; Journal ofOrganic Chemistry 44 (1979), pages 4294-4299 and Journal of OrganicChemistry 46, (1981), pages 1296-1309. Helv. Chim. Acta 56, 1802 (1973);Carbohydrate Research 26, 441 (1973); Chem. Ber. 102, 820 (1969) and J.Org. Chem. 27, 2107 (1962).

U.S. Pat. Nos. 4,116,669, 4,146,384 and 4,330,320 and German Pat. DS No.2,860,975 disclose a broad range of tetrahydrofuran derivatives andattribute herbicidal activity to these derivatives. U.S. Pat. Nos.3,919,252, 4,004,911 and 4,207,088 disclose dioxalane derivatives anddioxane derivatives and attribute grass herbicidal activity to thesederivatives. The sodium salt of2,3:4,6-bis-O-(1-methylethylidene)-O-(L-xylo-2-hexulofuranosonic acid)is sold as a pinching agent for azaleas and ornamentals and a growthretardant for shrubs, hedges and ground covers and is disclosed in U.S.Pat. No. 4,007,206.

The application of 5-C-alkyl-3-O-benzyl-1,2-O-isopropylidenea-D-xylo-pentodialdofuranose as herbicides and plant growth regulatorsis described by B. McCaskey in commonly assigned copending applicationSer. No. 387,590 filed June 11, 1982.

SUMMARY OF THE INVENTION

The present invention provides compounds having herbicidal activity andplant growth regulating activity and provides method and compositionsfor preventing or retarding unwanted vegetation and for controlling thegrowth of vegetation. Certain of the active compounds are composed onlyof hydrogen, oxygen and carbon and hence are very desirable from anenvironmental standpoint because they decompose into innocuouscarbon-oxygen moieties and water. I have further found that biologicalactivity in tetrahydrofuranyl nucleolus compounds is very unpredictable.For example, even though the compounds and compositions of the presentinvention exhibit very good herbicide activity, especially grasspre-emergence herbicide activity, and plant growth regulating activity,a number of closely related analogs and even the 3-epimers of thepresent compounds fail to exhibit such activity.

In one aspect the invention provides compounds having the formula##STR1## wherein R is alkyl having 1 through 4 carbon atoms or alkenylhaving 2 through 4 carbon atoms;

R¹ is 2-trifluoromethylphenyl, aryl having 6 through 10 carbon atoms, orsubstituted aryl having 1 through 4 substituents independently selectedfrom the group of lower alkyl, lower alkoxy, and halo, with the provisothat when R¹ is substituted aryl having more than two halo substituentsor is 2,3- or 3,4-dihalophenyl, then R is alkyl; and

R² or R³ is hydrogen or lower alkyl with the proviso that when R ismethyl, butyl, vinyl, 2-allyl, or but-1-enyl, R² is methyl and R³ ismethyl, then R¹ is not phenyl.

The present invention provides a herbicidal composition comprising acarrier and a herbicidally effective amount of a compound having theformula: ##STR2## wherein R is alkyl having 1 through 4 carbon atoms oralkenyl having 2 through 4 carbon atoms;

R¹ is 2-trifluoromethylphenyl or aryl having 6 through 10 carbon atoms,or substituted aryl having 1 through 4 substituents independentlyselected from the group of lower alkyl, lower alkoxy, halo, with theproviso than when R¹ is 2,4- or 3,4-dihalophenyl or has more than twohalo substituents, then R is said alkyl; and

R^(2') or R^(3') is hydrogen or lower alkyl.

The compounds of Formulas I and Ia are (D) optically active and cancomprise various isomers. Formulas (I) and (Ia) are intended torepresent the respective pure isomers as well as mixtures thereof,having the relative orientations at the 1-2, 3 and 4 positions shown inFormulas (I) and (Ia), and such respective isomers and mixtures areencompassed within the invention.

The present invention also provides a method for preventing orcontrolling the growth of unwanted vegetation, especially grasses, whichcomprises treating the growth medium and/or the foliage of suchvegetation with a herbicidally effective amount of the compound ofFormula Ia.

In another aspect, the present invention provides a plant growthregulating composition comprising a carrier and an effective amount ofthe plant growth regulating compound of the Formula Ia.

The present invention also provides a method for regulating plant growthwhich comprises treating the growth medium and/or the foliage of suchvegetation with a plant growth regulating effective amount of thecompound of Formula Ia.

The present invention also provides chemical intermediates and processesfor preparing the compounds of Formula Ia, for example, the compounds ofFormula Ia, wherein R is alkenyl, are useful as intermediates for thecompounds of Formula Ia, wherein R is alkyl.

The invention will be further described hereinbelow.

FURTHER DESCRIPTION OF THE INVENTION AND THE PREFERRED EMBODIMENTS

Illustrations of typical compounds of Formula (I) of the presentinvention can be had by reference to Examples 4, 7 and 10-16 set forthhereinbelow on pages 25, 35 and 40-45. In terms of substituents thepreferred compounds are those wherein R is alkyl, especially ethyl orpropyl. The preferred R¹ substituent is aryl and monosubstituted arylhaving a single substituent selected from the group lower alkyl, loweralkoxy, and halo. More preferably, R¹ is phenyl or 2-substituted phenylespecially phenyl, 2-methylphenyl or 2-halophenyl, especially2-fluorophenyl and 2-chlorophenyl. Preferably, R² and R³ areindependently hydrogen, methyl or ethyl and especially wherein R² and R³are each methyl.

The compounds of Formula Ia can be prepared via the processschematically represented by the following overall reaction equation.##STR3## wherein R, R¹, R² and R³ are as defined hereinabove, X ischloro or bromo and M is an alkali metal cation preferably sodium.

This process can be effected by contacting compound (A) with compound B,having the appropriate R¹ group, preferably in an inert organic solvent(e.g., tetrahydrofuran) and in the presence of an appropriate catalyst.This process is typically conducted at temperatures in the range ofabout from 0° to 140° C., preferably about from 25 to 75, for about from1 to 48 hours, preferably about from 3 to 12 hours. Typically about from1.0 to 1.25 moles, and preferably about from 1.0 to 1.1 moles of (B) areused per mole of compound A.

Suitable inert organic solvents which can be used include, for example,tetrahydrofuran, ethyl ether, xylene, toluene, dimethylsulfoxide,dimethylformamide, and the like and compatible mixtures thereof.Suitable catalysts which can be used include, for example,tetrabutylammonium iodide, tetrabutylammonium bromide,benzyltriethylammonium chloride, and the like. Typically a catalyst toreactant (A) ratio of about from 0.01 to 0.1 mole of catalyst per moleof A is used. Generally, best results are obtained using tetrahydrofuranas the solvent, tetrabutylammonium iodide as the catalyst and conductingthe reaction at about from 25° to 65° C. for about from 3 to 12 hours.Compound Ia can be separated from the reaction product mixture via anysuitable procedure; for example, chromatographically. For example, theseparation of the compound of Formula Ia, wherein R is methyl, R¹ isphenyl and R² and R³ are each methyl, is described in TetrahedronLetters No. 26, pp. 2447-2448 (1979).

Also, because of interfering reactions the compounds of Formula (Ia)wherein one or both of R^(2') or R^(3') are hydrogen are best preparedfrom the corresponding R² and R³ are each alkyl compounds of (Ia), aswill be subsequently described.

Compound A can be conveniently prepared by reacting the corresponding3-position hydroxy compound (i.e., M is hydrogen) with an alkali metalbase such as sodium hydride, potassium hydride, sodium hydroxide;potassium hydroxide and the like. Typically, this reaction is conductedat about from 0° to 140° C. preferably about from 0° to 65° C., forabout from 0.5 to 12 hours, preferably 0.5 to 1 hour, using about from1.0 to 1.1 moles of alkali metal base per mole of the hydroxy analog ofcompound A. Conveniently, the same inert organic solvents as describedabove are also used thus facilitating in situ preparation of compound IAas described above. The appropriate 3-hydroxy analogs wherein R is alkylhaving 2 through 4 carbon atoms can be prepared via the followingschematically represented process: ##STR4## wherein R' is alkyl having 1through 3 carbon atoms; R" is alkyl having 2 through 4 carbon atoms; R⁴O is an easily replaced group; X is chloro, bromo, or iodo and R^(2')and R^(3') are as defined hereinabove.

The first step of this process can be effected by contacting compound(C) with a Grignard reagent (D) having the appropriate R' group,preferably in an inert organic solvent (e.g., ethyl ether) and in thepresence of a suitable catalyst. This step is typically conducted attemperatures in the range of about from -78° to 65° C. preferably aboutfrom 25° to 65° C. for about from 1 to 24 hours. Conveniently thereaction is conducted using about from 2 to 20 preferably about from 5to 8 moles of compound D per mole of compound C.

Suitable inert organic solvents which can be used include, for example,ethyl ether and tetrahydrofuran and the like and compatible mixturesthereof. Suitable catalysts which can be used include, for example,dilithium tetrachlorocuprate (Li₂ CuCl₄); ferric chloride, and the likeand compatible mixtures thereof. Typically, a catalyst ratio of aboutfrom 0.001 to 0.01 mole of catalyst is used per mole of compound C.

As indicated above R⁴ O is a group which is easily replaced by the R'moiety of the Grignard reagent. R⁴ can, for example, be the group havingthe formula ##STR5## wherein R⁵ is phenyl, p-methylphenyl, lower alkyl.Very good results are typically obtained when R⁴ is tosyl or mesyl. Thecompounds of Formula C are generally known compounds and can be preparedby known procedures or by obvious modifications thereof. For example,the compounds of Formula C wherein R⁴ is tosyl or hydrogen and R² and R³are each methyl are described in Methods in Carbohydrate Chem. Vol. II249 (1963). Analogs having different R⁴ leaving groups can be obtainedby reacting the 3-position hydroxy compound with a halide derivative ofthe leaving group. The 1,2-O-isopropylidene substituent in the startingmaterial can be prepared by reacting the corresponding known1,2,3,5-tetrahydroxy analog with dimethyl ketone to yield thecorresponding 1,2:3,5-di-O-isopropylidene analog, see J. Amer. Chem.Soc. 77, 5900 (1955). The 3,5-O-alkylidene group can be selectivelycleaved without cleaving the 1,2-O-alkylidene group by mild acidhydrolysis, see also J. Amer. Chem. Soc., 77, 5900 (1955).1,2-O-isopropylidene-a-D-xylofuranose is also available commercially.Variation in the R² and R³ substituents can be obtained by replacingdimethyl ketone with the appropriate ketone or aldehyde, for example,diethyl ketone, acetaldehyde, formaldehyde, methyl ethyl ketone, etc.

The compounds of Formula A' wherein R is methyl can be obtained by theprocess schematically represented by the following overall reactionsequence: ##STR6## wherein M, R^(2') and R^(3') are as definedhereinabove, and Z is iodo or bromo.

Step 2' can be effected by contacting compound C with an alkali metalbromide or iodide (for example, sodium iodide) preferably a suitableinert organic solvent. This process is typically conducted attemperatures in the range of about from 50° to 100° C., preferably aboutfrom 80° to 90° C. for about from 5 to 48 hours. Typically about from1.0 to 5.0, preferably about from 1.5 to 2.0 moles of alkali halide areused per mole of compound (C). Suitable inert organic solvents which canbe used include for example 2-butanone, 2-pentanone, 3-pentanone, andthe like. Conveniently, the reaction is conducted at the refluxtemperature of the solvent. The synthesis of5-deoxy-5-iodo-1,2-O-isopropylidene-a-D-xylofuranose where Z is iodo andR² and R³ are each methyl is also described in J. Med. Chem. 22, 28(1979).

Step 3 is conducted by contacting compound E with hydrogen in thepresence of a suitable hydrogenation catalyst preferably in an inertorganic solvent and preferably in the presence of a suitable scavengerbase. This reaction is typically conducted at temperatures in the rangeof about from 0° to 50° C., conveniently 15° to 30° C., for about from 1to 5 hours. Typically about from 1 to 10 moles of hydrogen (H₂) is usedper mole of compound E. Suitable inert organic solvents which can beused include, for example, lower alkanols (e.g. methanol), and ethanol,ethyl acetate, and the like and compatible mixtures thereof.

Since this process yields hydrogen iodide or hydrogen bromide as abyproduct, it is preferred to conduct the reaction in the presence of ascavenger base to react with the hydrogen halide byproduct. Suitablescavenger bases which can be used include, for example, triethylamine,pyridine, and the like and compatible mixtures thereof.

Step 3 can also be conducted by employing LiAlH₄ as the reducing agent.The synthesis of 5-deoxy-1,2-O-isopropylidene-a-D-xylofuranose is alsodescribed in J. Chem. Soc. 2140 (1953).

The compounds of Formula Ia wherein R is isopropyl can be prepared bythe following schematically represented process: ##STR7##

The first step of this process can be effected by contacting thecompound of Formula K with triphenylmethyl phosphonium bromide andn-butyllithium preferably in an inert organic solvent. Typically, thisstep is conducted at temperatures in the range of about from 0° to 70°C., preferably about from 20° to 30° C., using about from 0.8 to 3 molesof triphenylmethyl phosphonium bromide and about from 0.5 to 3 moles ofbutyllithium per mole of compound K. Suitable solvents which can beused, include for example, tetrahydrofuran, benzene, hexane,dimethylsulfoxide, dimethoxyethane and the like. The alkene product ofthis reaction can be separated or desired as the product or hydrogenatedto the alkyl. The second step is thus conducted by contacting the alkenereaction product with hydrogen in the presence of a suitablehydrogenation catalyst (for example palladium on carbon) in an inertorganic solvent. Typically, the hydrogenation is conducted attemperatures in the range of about from 15° to 50° C. using about from0.9 to 3 moles of hydrogen per mole of intermediate. Typically, thereaction is conducted by simply contacting the alkene product withhydrogen until no further hydrogen is taken up. The same inert organicsolvents as used for the first step can also be used for thehydrogenation and the hydrogenation can be conveniently conducted insitu.

The compounds of Formula Ia wherein R is vinyl can be prepared by theprocess schematically represented by the following overall reactionequation sequence: ##STR8## wherein R¹, R², R³, M, and Z are as definedhereinabove.

The first step of this process can be effected in the same manner asdescribed hereinabove, with respect to the reaction of compound A tocompound Ia.

The starting material of Formula F can be prepared from the known1,2,3,5,6-pentahydroxy substrate by reaction with the appropriate ketoneas already described above.

In the next step the 5,6-O-alkylidenyl group is selectively cleaved.This can be conveniently effected by mild acid hydrolysis, for example,by contacting compound G with aqueous acetic acid at temperatures in therange of about from 25° to 100° C.; preferably about from 40° to 60° C.for about from 1 to 48 hours. Conveniently, the hydrolysis is conductedin a suitable inert organic solvent, such as for example aqueous aceticacid, aqueous trifluoroacetic acid, aqueous hydrochloric acid, and thelike, and compatible mixtures thereof. The preparation of the compoundsof Formulas F, G, and H, wherein R¹ is phenyl and R² and R³ are eachmethyl, is also described in methods in Carbohydrate Chem. Vol. VI 286and 297 (1972).

The last step, conversion of the 5,6-dihydroxy group to the olefin, isconveniently conducted in two phases. The first phase can be conductedby contacting compound H with a trialkylorthoformate (e.g.triethylorthoformate) under protic conditions to yield the corresponding5,6-O-alkoxyalkylene derivative of compound H.

This phase is conveniently conducted at temperatures in the range ofabout from 100 to the boiling point of the trialkylorthoformate,preferably 120° to 146° C. for about from 3 to 12 hours. Preferably,small amount of a weak acid (e.g. acetic acid) is added to the reactionmixture to ensure protic conditions.

The next phase of this step can be effected by heating the product ofthe first phase in the presence of an acid. This phase is typicallyconducted at temperatures in the range of about from 160° to 180° C. forabout from 3 to 6 hours. Suitable acids which can be used include, forexample, triphenylacetic acid, benzoic acid, p-chlorobenzoic acid, andthe like. The example wherein R¹ is phenyl, and R² and R³ are eachmethyl, is described in Methods in Carbohydrate Chem. Vol. VI 297(1972).

The compounds of Formula Ia wherein R is alkenyl having 3 or 4 carbonatoms having its double bond at the 1' position can be made by thefollowing procedure: ##STR9## wherein R'" is alkyl having 1 to 2 carbonatoms; and R¹, R², and R³ are as defined hereinabove.

This first step of this process can be effected by contacting compound(H) with an alkali metal metaperiodate (e.g. sodium metaperiodate) orlead tetraacetate preferably in an inert organic solvent. Typically,this process is conducted at temperatures in the range of about from 0°to 70° C., preferably 0° to 30° C. using about from 1.0 to 1.25 moles ofalkali metal metaperiodate per mole of compound (H). Suitable solventswhich can be used include, for example, tetrahydrofuran, methanol,benzene, toluene, water, and the like.

The second step can be effected by contacting compound J withtriphenylethyl or triphenylpropyl phosphonium bromide andn-butyllithium, preferably in an inert organic solvent. Typically, thisprocess is conducted at temperatures in the range of about from 0° to70° C., preferably 20° to 30° C., using about from 0.8 to 3 moles of thebromide and about from 0.5 to 3 moles of butyllithium per mole ofcompound (J). Suitable inert organic solvents which can be used include,for example, tetrahydrofuran, benzene, hexane, dimethylsulfoxide,dimethoxyethane, and the like.

The preparation of the compound wherein R'" is ethyl, R¹ is phenyl andR² and R³ are each methyl, is also described in Tetrahedron Letters No.35, pp. 3233-3236 (1978).

The compounds of Formula (Ia) wherein R is alkenyl having itsunsaturation at the 2' position can be prepared by contacting thecorresponding compound of Formula Ia but wherein R is formylmethyl[Helv. Chim. Acta 63, 1644 (1980)] with triphenylmethyl ortriphenylethyl, phosphonium bromide and butyllithium in an inert organicsolvent (e.g. tetrahydrofuran). This reaction can be conducted in thesame manner as described for the second step hereinabove.

The compounds of Formula (Ia) wherein R is alkenyl having itsunsaturation at the 3' position can be prepared by contacting thecorresponding compound of Formula Ia but wherein R isp-toluenesulfonyloxymethyl with the Grignard reagent of allyl bromide orchloride preferably in an inert organic solvent (e.g., ethyl ether ortetrahydrofuran) and in the presence of a suitable catalyst in the samemanner as the Grignard reaction as previously described above.

The compounds of Formula Ia wherein R is alkyl having 2 to 4 carbonatoms can also be made by hydrogenation of the corresponding R isalkenyl compound, for example, via hydrogenation in the presence of asuitable hydrogenation catalyst such as, for example, palladium oncarbon.

The compounds of Formula (Ia) wherein one or both of R^(2') and/orR^(3') are hydrogen can be prepared from the corresponding R^(2') andR^(3') are each alkyl compound of Formula (Ia). This can be convenientlyeffected by contacting the R², R³ alkyl compound of Formula (I) with analdehyde having the appropriate R², R³ substitution. For example,compound (Ia) wherein R^(2') and R^(3') are each hydrogen can beprepared by using paraformaldehyde and glacial acetic acid, followed bycontact with a small amount of a strong acid (e.g. concentrated sulfuricacid), whereas the compound (Ia) wherein one of R^(2') and R^(3') ishydrogen and the other is methyl can be prepared by cleaving the1,2-O-alkylidene group by acid hydrolysis and then contacting thecleaved product with acetaldehyde. Typically, the first step of thisreaction where the 1,2-O-alkylidene group is cleaved by acid can beconveniently effected by mild acid hydrolysis, for example, bycontacting the compound with aqueous trifluoroacetic acid, preferably atroom temperature (about 20°-25° C.) for about 0.5-5 hours. Conveniently,the hydrolysis is conducted in a suitable inert organic solvent, such asfor example, aqueous acetic acid, aqueous trifluoroacetic acid, aqueoushydrochloric acid and the like, and compatible mixtures thereof. Thesecond step of this reaction is typically conducted at temperatures inthe range of about from 25° C. to the boiling point of the aldehyde forabout from 1 to 24 hours using about from 1 to 10 moles of aldehyde permole of compound (Ia) in the presence of a catalytic amount of acid(e.g., concentrated sulfuric acid or p-toluenesulfonic acid) and adehydrating agent such as anhydrous copper sulfate, or molecular sieves.

Variation in the R^(2'), R^(3') alkyl substituents can also be effectedin the compound (Ia) by cleaving the 1,2-O-alkylidene group by acidhydrolysis and then contacting the cleaved product with the appropriateketone having the desired R^(2'), R^(3') substitution in the presence ofa dehydrating agent, as previously described with respect to theintermediates.

In the above-described processes, it is generally preferable to separatethe respective products before proceeding with the next step in thereaction sequence unless expressly stated otherwise. These products canbe recovered from their respective reaction product mixtures by anysuitable separation and purification procedure, such as, for example,recrystallization and chromatography. Suitable separation andpurification procedures are, for example, illustrated in the Examplesset forth hereinbelow. Also generally it is preferred to use theappropriate isomer starting material having the same orientation ascompound Ia. However, isomer mixtures of starting materials can also beused. In this case the product will be a mixture of compound Ia and itsisomers. Compound Ia can then be separated from the isomer mixture orapplied as a mixture.

Generally, the reactions described above are conducted as liquid phasereaction and hence pressure is generally not significant except as itaffects temperature (boiling point) where reactions are conducted atreflux. Therefore, these reactions are generally conducted at pressuresof from 300 to 3000 mm of mercury and conveniently are conducted atabout atmospheric or ambient pressure. In the case of the hydrogenationdescribed above, the hydrogenation is typically conducted by bubblinghydrogen through the substrate, dissolved in a solvent, or placing thesubstrate solution under hydrogen. Thus, the hydrogenation is typicallyconducted under a modest pressure, typically about from 800 to 3000 mmHg.

It should also be appreciated that where typical or preferred processconditions (e.g., reaction temperatures, times, mol ratios of reactants,solvents, etc.) have been given, that other process conditions couldalso be used, although typically with poor yields or economies. Optimumreaction conditions (e.g., temperature, reaction time, mol ratios,solvents, etc.) may vary with the particular reagents or organicsolvents used but can be determined by routine optimization procedures.

Where optical isomer mixtures are obtained, the respective opticalisomers can be obtained by conventional resolution procedures, forexample, by converting the isomer mixture to an acid derivative andreacting with an optically active base which will yield a mixture ofoptical salts, of the desired compound, which can be resolved byconventional procedures (e.g., crystallization) into the respective plusand minus optical salts.

Definitions

As used herein the following terms have the following meanings unlessexpressly stated to the contrary:

The term "lower alkyl" refers to both straight- and branched-chain alkylgroups having a total of from 1 through 4 carbon atoms and includesprimary, secondary and tertiary alkyl groups. Typical lower alkylsinclude, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl,t-butyl.

The term "lower alkenyl" refers to alkenyl groups having 2 through 4carbon atoms and includes for example vinyl; 1-propenyl, 2-propenyl,1-methylvinyl, 1-butenyl, 2-methylprop-1-enyl and the like.

The term "halo" refers to the group of fluoro, chloro, bromo and iodo.

The term "aryl" refers to aryl groups having 6 through 10 carbon atomsand includes, for example, phenyl, naphthyl, indenyl, and the like.

The term "substituted aryl" refers to aryl groups having 1 through 4substituents independently selected from the group of lower alkyl, loweralkoxy and halo. Typical substituted aryl includes, for example,2-fluorophenyl, 2-chlorophenyl, 2,6-dimethylphenyl, 2-methylphenyl,2,4-dimethylphenyl, 2,5-dimethylphenyl, 2,4-dichlorophenyl,2-methoxyphenyl and the like.

The term "room temperature" or "ambient temperature" refers to about20°-25° C.

Utility

The compounds of Formula (Ia) exhibit both pre-emergence andpost-emergence herbicide activity and exhibit especially goodpre-emergence grass herbicide activity. Further, by proper reduction ofthe dosage, the compounds can be safely applied as selectivepre-emergence grass herbicides to prevent or reduce the growth ofgrasses amongst broad leaf crops such as soybean. The preferredherbicidal compounds of Formula (I) are those wherein R is ethyl orpropyl and especially the compound wherein R is ethyl.

Generally, for post-emergent applications, the herbicidal compounds areapplied directly to the foliage or other plant parts. For pre-emergenceapplications, the herbicidal compounds are applied to the growingmedium, or prospective growing medium, of the plant. The optimum amountof the herbicidal compound or composition will vary with the particularplant species, and the extent of part plant growth and the particularpart of the plant which is contacted. The optimum dosage will also varywith the general location, or environment, of application (e.g.,sheltered areas such as greenhouses compared to exposed areas such asfields), and type and degree of control desired. Generally, for bothpre- and post-emergent control, the present compounds are applied atrates of about from 0.2 to 60 kg/ha, preferably about from 0.5 to 10kg/ha.

Also, although in theory the compounds can be applied undiluted, inactual practice they are generally applied as a composition orformulation comprising an effective amount of the compound(s) and anacceptable carrier. An acceptable carrier (algriculturally acceptablecarrier) is one which does not significantly adversely affect thedesired biological effect achieved by the active compounds, save todilute it. Typically, the composition contains about from 0.05 to 95% byweight of the compound of Formula (I) or mixtures thereof. Concentratescan also be made having higher concentrations designed for dilutionprior to application. The carrier can be a solid, liquid, or aerosol.The actual compositions can take the form of granules, powders, dusts,solutions, emulsions, slurries, aerosols, and the like.

Suitable solid carriers which can be used include, for example, naturalclays (such as kaolin, attapulgite, montmorillonite, etc.), talcs,pyrophyllite, diatomaceous silica, synthetic fine silica, calciumaluminosilicate, tricalcium phosphate, and the like. Also, organicmaterials, such as, for example, walnut shell flour, cotton-seed hulls,wheat flour, wood flour, wood bark flour, and the like can also be usedas carriers. Suitable liquid diluents which can be used include, forexample, water, organic solvents (e.g., hydrocarbons such as benzene,toluene, dimethylsulfoxide, kerosene, diesel fuel, fuel oil, petroleumnaphtha, etc.), and the like. Suitable aerosol carriers which can beused include conventional aerosol carriers such as halogenated alkanes,etc.

The composition can also contain various promoters and surface-activeagents which enhance the rate of transport of the active compound intothe plant tissue such as, for example, organic solvents, wetting agentsand oils, and in the case of compositions designed for pre-emergenceapplication agents which reduce the leachability of the compound.

The composition can also contain various compatible adjuvants,stabilizers, conditioners, insecticides, fungicides, and if desired,other herbicidally active compounds.

The compounds of the present invention also exhibit plant growthregulating activity and especially root growth inhibition; foliageregrowth inhibition and crop enhancement. The former activity is usefulwhere top growth is desirable. Foliage regrowth inhibition is desirablein cases such as the harvesting of cotton. In harvesting cotton,defoliants and desiccants are frequently used to remove the leaves ofthe cotton plant thus making the cotton more accessible. In such casesregrowth inhibitors are useful to inhibit the regrowth of leaves, beforeharvesting is completed. Crop enhancement is produced by pinching andincreasing crop bearing branching in crops such as soy bean.

The present compounds of Formula (I) can be applied in pure form, butmore pregmatically, as in the case of herbicide application, are appliedin combination with a carrier. The same types of carriers as set forthhereinabove with respect to the herbicide compositions can also be used.Depending on the desired application, the plant growth regulatingcomposition can also contain, or be applied in combination with othercompatible ingredients such as desiccants, defoliants, surface-activeagents, adjuvants, fungicides, insecticides and selective herbicides.Typically, the plant growth regulating composition will contain a totalof about from 0.005 to 90 wt. %, of the compound(s) of Formula (Ia)depending on whether the composition is intended to be applied directlyor diluted first.

A further understanding of the invention can be had in the followingnon-limiting Preparation and Examples. Wherein, unless expressly statedto the contrary, all temperatures and temperature ranges refer to theCentigrade system and the term "ambient" or "room temperature" refers toabout 20°-25° C. The term "percent" or "%" refers to weight percent andthe term "mole" or "moles" refers to gram moles. The term "equivalent"refers to a quantity of reagent equal in moles, to the moles of thepreceding or succeeding reactant recited in that example in terms offinite moles or finite weight or volume. Where given, proton-magneticresonance spectrum (p.m.r. or n.m.r.) were determined at 60 mHz, signalsare assigned as singlets (s), broad singlets (bs), doublets (d), doubledoublets (dd), triplets (t), double triplets (dt), quartets (q), andmultiplets (m); and cps refers to cycles per second. Also wherenecessary examples are repeated to provide additional starting materialfor subsequent examples.

EXAMPLE 1 1,2-O-Isopropylidene-a-D-xylofuranose

In this example 5 ml of concentrated 96 wt. % sulfuric acid; 100 g ofanhydrous cupric sulfate and 50 g of D-xylose were sequentially added to1 liter of acetone. The resulting mixture was then stirred vigorouslyfor 25 hours at room temperature under anhydrous conditions. Thesolution was then filtered and washed with acetone. 16 ml of aqueous 15N. Ammonium hydroxide was then added to the filtrate to render it basic.The filtrate was then filtered to remove solids and evaporated underreduced pressure. The above procedure was repeated, affording a combinedyield of 123 g of crude product which was then distilled at 114°-118° C.under 3 mm mercury pressure affording 102 g of1,2:3,5-di-O-isopropylidene-a-D-xylofuranose as a thick light yellowsyrup. This product was confirmed by nmr analysis.

100 g of the above product was then warmed until molten in a roundbottomed flask equipped with a mechanical stirrer and then cooled toroom temperature and 550 ml of aqueous 0.2 wt. % hydrochloric acid werethen added. The resulting mixture was stirred for 25 minutes at roomtemperature and then filtered. The filtrate was then neutralized to pH7-8 by the controlled addition of sodium bicarbonate, and thenevaporated to dryness under reduced pressure affording a yellow slurry.This slurry was dissolved in 500 ml of chloroform and then filtered. Thefiltrate was dried over anhydrous magnesium sulfate, and evaporatedaffording a yellow syrup. Examination of the syrup with thin layerchromatography showed that the reaction had only gone to about 50%completion. Accordingly, the syrup was redissolved in aqueous 0.2 wt. %hydrochloric acid and the procedure repeated affording 61.9 g of thetitle product.

Similarly, by following the same procedure by using the correspondingaldehyde or ketone in place of acetone, the following compounds can berespectively prepared:

1,2-O-ethylidene-a-D-xylofuranose;

1,2-O-(1-methylpropylidene)-a-D-xylofuranose;

1,2-O-(1-propylpentylidene)-a-D-xylofuranose; and

1,2-O-(1,2-dimethylpropylidene)-a-D-xylofuranose.

EXAMPLE 2 1,2-O-Isopropylidene-5-O-tosyl-a-D-xylofuranose

In this example a solution containing 68 g of para-toluenesulfonylchloride dissolved in 124 ml of methylene chloride was slowly addeddropwise to an anhydrous solution containing 61.9 g of1,2-O-isopropylidene-a-D-xylofuranose in 310 ml of pyridine at 0° C. Themixture was stirred for one hour at 0° C. and then allowed to standovernight at room temperature. The solution was then extracted threetimes with 200 ml of methylene chloride. The combined organic extractswere washed with cold dilute aqueous sulfuric acid to remove thepyridine, and then washed with water until neutral. The washed extractwas then dried over magnesium sulfate and evaporated to dryness undervacuum affording 110 g of solid product. The solid product was thenrecrystallized twice from ethyl acetate affording the title compound,m.p. 134°-136.5° C.

Similarly, by following the same procedure using the correspondingproducts of Example 1 as starting materials, the following compounds canbe respectfully prepared:

1,2-O-ethylidene-5-O-tosyl-a-D-xylofuranose;

1,2-O-(1-methylpropylidene)-5-O-tosyl-a-D-xylofuranose;

1,2-O-(1-propylpentylidene)-5-O-tosyl-a-D-xylofuranose; and

1,2-O-(1,2-dimethylpropylidene)-5-O-tosyl-a-D-xylofuranose.

EXAMPLE 3 1,2-O-Isopropylidene-5-Deoxy-5-C-Ethyl-a-D-xylofuranose

In this example, 0.1 mmoles of dilithium tetrachlorocuprate (Li₂ CuCl₄)in 1 ml of tetrahydrofuran was added to 0.14 moles of ethyl magnesiumbromide in 100 ml of ethyl ether and then cooled to -78° C. 6.9 g (0.02moles) of 1,2-O-isopropylidene-5-O-tosyl-a-D-xylofuranose dissolved in30 ml of tetrahydrofuran was then added. The resulting mixture was thenstirred for 2 hours at room temperature and then refluxed overnight(about 12 hours). The mixture was then poured into a dilute aqueoussulfuric acid and ice mixture and then extracted three times with 50 mlof ethyl ether. The ether extracts were then combined and washed twicewith 50 ml water, then dried over magnesium sulfate, and evaporated todryness under a vacuum. The resulting residue was then crystallized froma mixture of ethyl ether and hexane affording 3.4 g of the titlecompound, m.p. 58°-60° C.

Similarly, by the following the same procedure but using thecorresponding products of Example 2 as starting materials, the followingcompounds can be respectively prepared:

1,2-O-ethylidene-5-deoxy-5-C-ethyl-a-D-xylofuranose;

1,2-O-(1-methylpropylidene)-5-deoxy-5-C-ethyl-a-D-xylofuranose;

1,2-O-(1-propylpentylidene)-5-deoxy-5-C-ethyl-a-D-xylofuranose; and

1,2-O-(1,2-dimethylpropylidene)-5-deoxy-5-C-ethyl-a-D-xylofuranose.

Similarly, by following the same procedure but using methyl magnesiumbromide in place of ethyl magnesium bromide, the following compounds canbe respectively prepared:

1,2-O-isopropylidene-5-deoxy-5-C-methyl-a-D-xylofuranose;

1,2-O-ethylidene-5-deoxy-5-C-methyl-a-D-xylofuranose;

1,2-O-(1-methylpropylidene)-5-deoxy-5-C-methyl-a-D-xylofuranose;

1,2-O-(1-propylpentylidene)-5-deoxy-5-C-methyl-a-D-xylofuranose; and

1,2-O-(1,2-dimethylpropylidene)-5-deoxy-5-C-methyl-a-D-xylofuranose.

Similarly, by following the same procedure but using propyl magnesiumbromide and isopropyl magnesium bromide respectively in place of ethylmagnesium bromide, the corresponding 5-C-propyl and 5-C-isopropylhomologs of the above compounds can be respectively prepared.

EXAMPLE 41,2-O-isopropylidene-3-O-benzyl-5-deoxy-5-C-ethyl-a-D-xylofuranose

In this example 1.15 g (0.024 mole) of 50 wt. % sodium hydride wasslowly added to a solution containing 4.0 g of1,2-O-isopropylidene-5-deoxy-5-C-ethyl-a-D-xylofuranose in 20 ml oftetrahydrofuran, under a nitrogen atmosphere, at room temperature. After15 minutes, 0.3 g of tetrabutyl ammonium iodide and 4.1 g (0.024 moles)of benzyl bromide were added and the reaction mixture was then stirredovernight at room temperature. The reaction mixture was thenconcentrated by evaporation under vacuum and then 100 ml of water and100 ml of methylene chloride were added. The resulting organic layer wasthen separated and washed twice with 100 ml portions of water and thendried over anhydrous magnesium sulfate and concentrated by vacuumevaporation. The resulting concentrated liquid was then dissolved in 100ml of acetonitrile and then washed twice with 20 ml of hexane to removemineral oil. The liquid was then evaporated under vacuum affording aliquid which was then distilled at 152°-155° C. under 1 mm of mercurypressure affording 3.4 g of the title compound.

Similarly, by following the same procedure but using the correspondingproducts of Example 3 as starting materials, the following compounds canbe respectively prepared:

1,2-O-ethylidene-3-O-benzyl-5-deoxy-5-C-ethyl-a-D-xylofuranose;

1,2-O-(1-methylpropylidene)-3-O-benzyl-5-deoxy-5-C-ethyl-a-D-xylofuranose;

1,2-O-(1-propylpentylidene)-3-O-benzyl-5-deoxy-5-C-ethyl-a-D-xylofuranose;and

1,2-O-(1,2-dimethylpropylidene)-3-O-benzyl-5-deoxy-5-C-ethyl-a-D-xylofuranose;

1,2-O-isopropylidene-3-O-benzyl-5-deoxy-5-C-methyl-a-D-xylofuranose;

1,2-O-ethylidene-3-O-benzyl-5-deoxy-5-C-methyl-a-D-xylofuranose;

1,2-O-(1-methylpropylidene)-3-O-benzyl-5-deoxy-5-C-methyl-a-D-xylofuranose;

1,2-O-(1-propylpentylidene)-3-O-benzyl-5-deoxy-5-C-methyl-a-D-xylofuranose;

1,2-O-(1,2-dimethylpropylidene)-3-O-benzyl-5-deoxy-5-C-methyl-a-D-xylofuranose;

1,2-O-isopropylidene-3-O-benzyl-5-deoxy-5-C-propyl-a-D-xylofuranose;

1,2-O-ethylidene-3-O-benzyl-5-deoxy-5-propyl-a-D-xylofuranose;

1,2-O-(1-methylpropylidene)-3-O-benzyl-5-deoxy-5-C-propyl-a-D-xylofuranose;

1,2-O-(1-propylpentylidene)-3-O-benzyl-5-deoxy-5-C-propyl-a-D-xylofuranose;

1,2-O-(1,2-dimethylpropylidene)-3-O-benzyl-5-deoxy-5-C-propyl-a-D-xylofuranose;

1,2-O-isopropylidene-3-O-benzyl-5-deoxy-5-C-isopropyl-a-D-xylofuranose;

1,2-O-ethylidene-3-O-benzyl-5-deoxy-5-C-isopropyl-a-D-xylofuranose;

1,2-O-(1-methylpropylidene)-3-O-benzyl-5-deoxy-5-C-isopropyl-a-D-xylofuranose;

1,2-O-(1-propylpentylidene)-3-O-benzyl-5-deoxy-5-C-isopropyl-a-D-xylofuranose;

1,2-O-(1,2-dimethylpropylidene)-3-O-benzyl-5-deoxy-5-C-isopropyl-a-D-xylofuranose.

Similarly, by following the same procedure but using 2-chlorobenzylbromide in place of benzyl bromide, the following compounds can berespectively prepared:

1,2-O-isopropylidene-3-O-(2'-chlorobenzyl)-5-deoxy-5-C-ethyl-a-D-xylofuranose;

1,2-O-ethylidene-3-O-(2'-chlorobenzyl)-5-deoxy-5-C-ethyl-a-D-xylofuranose;

1,2-O-(1-methylpropylidene)-3-O-(2'-chlorobenzyl)-5-deoxy-5-C-ethyl-a-D-xylofuranose;

1,2-O-(1-propylpentylidene)-3-O-(2'-chlorobenzyl)-5-deoxy-5-C-ethyl-a-D-xylofuranose;and

1,2-O-(1,2-dimethylpropylidene)-3-O-(2'-chlorobenzyl)-5-deoxy-5-C-ethyl-a-D-xylofuranose;

1,2-O-isopropylidene-3-O-(2'-chlorobenzyl)-5-deoxy-5-C-methyl-a-D-xylofuranose;

1,2-O-ethylidene-3-O-(2'-chlorobenzyl)-5-deoxy-5-C-methyl-a-D-xylofuranose;

1,2-O-(1-methylpropylidene)-3-O-(2'-chlorobenzyl)-5-deoxy-5-C-methyl-a-D-xylofuranose;

1,2-O-(1-propylpentylidene)-3-O-(2'-chlorobenzyl)-5-deoxy-5-C-methyl-a-D-xylofuranose;

1,2-O-(1,2-dimethylpropylidene)-3-O-(2'-chlorobenzyl)-5-deoxy-5-C-methyl-a-D-xylofuranose;

1,2-O-isopropylidene-3-O-(2'-chlorobenzyl)-5-deoxy-5-C-propyl-a-D-xylofuranose;

1,2-O-ethylidene-3-O-(2'-chlorobenzyl)-5-deoxy-5-C-propyl-a-D-xylofuranose;

1,2-O-(1-methylpropylidene)-3-O-(2'-chlorobenzyl)-5-deoxy-5-C-propyl-a-D-xylofuranose;

1,2-O-(1-propylpentylidene)-3-O-(2'-chlorobenzyl)-5-deoxy-5-C-propyl-a-D-xylofuranose;

1,2-O-(1,2-dimethylpropylidene)-3-O-(2'-chlorobenzyl)-5-deoxy-5-C-propyl-a-D-xylofuranose;

1,2-O-isopropylidene-3-O-(2'-chlorobenzyl)-5-deoxy-5-C-isopropyl-a-D-xylofuranose;

1,2-O-ethylidene-3-O-(2'-chlorobenzyl)-5-deoxy-5-C-isopropyl-a-D-xylofuranose;

1,2-O-(1-methylpropylidene)-3-O-(2'-chlorobenzyl)-5-deoxy-5-C-isopropyl-a-D-xylofuranose;

1,2-O-(1-propylpentylidene)-3-O-(2'-chlorobenzyl)-5-deoxy-5-C-isopropyl-a-D-xylofuranose;

1,2-O-(1,2-dimethylpropylidene)-3-O-(2'-chlorobenzyl)-5-deoxy-5-C-isopropyl-a-D-xylofuranose.

Similarly, by following the same procedure but respectively using2-fluorobenzyl bromide; 2-trifluoromethylbenzyl bromide;2,6-dimethylbenzyl bromide; 2-methoxybenzyl bromide; and 2-naphthamethylbromide; the following compounds can be respectively prepared:

1,2-O-isopropylidene-3-O-(2'-fluorobenzyl)-5-deoxy-5-C-ethyl-a-D-xylofuranose;

1,2-O-ethylidene-3-O-(2'-fluorobenzyl)-5-deoxy-5-C-ethyl-a-D-xylofuranose;

1,2-O-(1-methylpropylidene)-3-O-(2'-fluorobenzyl)-5-deoxy-5-C-ethyl-a-D-xylofuranose;

1,2-O-(1-propylpentylidene)-3-O-(2'-fluorobenzyl)-5-deoxy-5-C-ethyl-a-D-xylofuranose;

1,2-O-(1,2-dimethylpropylidene)-3-O-(2'-fluorobenzyl)-5-deoxy-5-C-ethyl-a-D-xylofuranose;

1,2-O-isopropylidene-3-O-(2'-fluorobenzyl)-5-deoxy-5-C-methyl-a-D-xylofuranose;

1,2-O-ethylidene-3-O-(2'-fluorobenzyl)-5-deoxy-5-C-methyl-a-D-xylofuranose;

1,2-O-(1-methylpropylidene)-3-O-(2'-fluorobenzyl)-5-deoxy-5-C-methyl-a-D-xylofuranose;

1,2-O-(1-propylpentylidene)-3-O-(2'-fluorobenzyl)-5-deoxy-5-C-methyl-a-D-xylofuranose;

1,2-O-(1,2-dimethylpropylidene)-3-O-(2'-fluorobenzyl)-5-deoxy-5-C-methyl-a-D-xylofuranose;

1,2-O-isopropylidene-3-O-(2'-fluorobenzyl)-5-deoxy-5-C-propyl-a-D-xylofuranose;

1,2-O-ethylidene-3-O-(2'-fluorobenzyl)-5-deoxy-5-C-propyl-a-D-xylofuranose;

1,2-O-(1-methylpropylidene)-3-O-(2'-fluorobenzyl)-5-deoxy-5-C-propyl-a-D-xylofuranose;

1,2-O-(1-propylpentylidene)-3-O-(2'-fluorobenzyl)-5-deoxy-5-C-propyl-a-D-xylofuranose;

1,2-O-(1,2-dimethylpropylidene)-3-O-(2'-fluorobenzyl)-5-deoxy-5-C-propyl-a-D-xylofuranose;

1,2-O-isopropylidene-3-O-(2'-fluorobenzyl)-5-deoxy-5-C-isopropyl-a-D-xylofuranose;

1,2-O-ethylidene-3-O-(2'-fluorobenzyl)-5-deoxy-5-C-isopropyl-a-D-xylofuranose;

1,2-O-(1-methylpropylidene)-3-O-(2'-fluorobenzyl)-5-deoxy-5-C-isopropyl-a-D-xylofuranose;

1,2-O-(1-propylpentylidene)-3-O-(2'-fluorobenzyl)-5-deoxy-5-C-isopropyl-a-D-xylofuranose;

1,2-O-(1,2-dimethylpropylidene)-3-O-(2'-fluorobenzyl)-5-deoxy-5-C-isopropyl-a-D-xylofuranose;

1,2-O-isopropylidene-3-O-(2'-trifluoromethylbenzyl)-5-deoxy-5-C-ethyl-a-D-xylofuranose;

1,2-O-ethylidene-3-O-(2'-trifluoromethylbenzyl)-5-deoxy-5-C-ethyl-a-D-xylofuranose;

1,2-O-(1-methylpropylidene)-3-O-(2'-trifluoromethylbenzyl)-5-deoxy-5-C-ethyl-a-D-xylofuranose;

1,2-O-(1-propylpentylidene)-3-O-(2'-trifluoromethylbenzyl)-5-deoxy-5-C-ethyl-a-D-xylofuranose;

1,2-O-(1,2-dimethylpropylidene)-3-O-(2'-trifluoromethylbenzyl)-5-deoxy-5-C-ethyl-a-D-xylofuranose;

1,2-O-isopropylidene-3-O-(2'-trifluoromethylbenzyl)-5-deoxy-5-C-methyl-a-D-xylofuranose;

1,2-O-ethylidene-3-O-(2'-trifluoromethylbenzyl)-5-deoxy-5-C-methyl-a-D-xylofuranose;

1,2-O-(1-methylpropylidene)-3-O-(2'-trifluoromethylbenzyl)-5-deoxy-5-C-methyl-a-D-xylofuranose;

1,2-O-(1-propylpentylidene)-3-O-(2'-trifluoromethylbenzyl)-5-deoxy-5-C-methyl-a-D-xylofuranose;

1,2-O-(1,2-dimethylpropylidene)-3-O-(2'-trifluoromethylbenzyl)-5-deoxy-5-C-methyl-a-D-xylofuranose;

1,2-O-isopropylidene-3-O-(2'-trifluoromethylbenzyl)-5-deoxy-5-C-propyl-a-D-xylofuranose;

1,2-O-ethylidene-3-O-(2'-trifluoromethylbenzyl)-5-deoxy-5-C-propyl-a-D-xylofuranose;

1,2-O-(1-methylpropylidene)-3-O-(2'-trifluoromethylbenzyl)-5-deoxy-5-C-propyl-a-D-xylofuranose;

1,2-O-(1-propylpentylidene)-3-O-(2'-trifluoromethylbenzyl)-5-deoxy-5-C-propyl-a-D-xylofuranose;

1,2-O-(1,2-dimethylpropylidene)-3-O-(2'-trifluoromethylbenzyl)-5-deoxy-5-C-propyl-a-D-xylofuranose;

1,2-O-isopropylidene-3-O-(2'-trifluoromethylbenzyl)-5-deoxy-5-C-isopropyl-a-D-xylofuranose;

1,2-O-ethylidene-3-O-(2'-trifluoromethylbenzyl)-5-deoxy-5-C-isopropyl-a-D-xylofuranose;

1,2-O-(1-methylpropylidene)-3-O-(2'-trifluoromethylbenzyl)-5-deoxy-5-C-isopropyl-a-D-xylofuranose;

1,2-O-(1-propylpentylidene)-3-O-(2'-trifluoromethylbenzyl)-5-deoxy-5-C-isopropyl-a-D-xylofuranose;

1,2-O-(1,2-dimethylpropylidene)-3-O-(2'-trifluoromethylbenzyl)-5-deoxy-5-C-isopropyl-a-D-xylofuranose;

1,2-O-isopropylidene-3-O-(2',6'-dimethylbenzyl)-5-deoxy-5-C-ethyl-a-D-xylofuranose;

1,2-O-ethylidene-3-O-(2',6'-dimethylbenzyl)-5-deoxy-5-C-ethyl-a-D-xylofuranose;

1,2-O-(1-methylpropylidene)-3-O-(2',6'-dimethylbenzyl)-5-deoxy-5-C-ethyl-a-D-xylofuranose;

1,2-O-(1-propylpentylidene)-3-O-(2',6'-dimethylbenzyl)-5-deoxy-5-C-ethyl-a-D-xylofuranose;

1,2-O-(1,2-dimethylpropylidene)-3-O-(2',6'-dimethylbenzyl)-5-deoxy-5-C-ethyl-a-D-xylofuranose;

1,2-O-isopropylidene-3-O-(2',6'-dimethylbenzyl)-5-deoxy-5-C-methyl-a-D-xylofuranose;

1,2-O-ethylidene-3-O-(2',6'-dimethylbenzyl)-5-deoxy-5-C-methyl-a-D-xylofuranose;

1,2-O-(1-methylpropylidene)-3-O-(2',6'-dimethylbenzyl)-5-deoxy-5-C-methyl-a-D-xylofuranose;

1,2-O-(1-propylpentylidene)-3-O-(2',6'-dimethylbenzyl)-5-deoxy-5-C-methyl-a-D-xylofuranose;

1,2-O-(1,2-dimethylpropylidene)-3-O-(2',6'-dimethylbenzyl)-5-deoxy-5-C-methyl-a-D-xylofuranose;

1,2-O-isopropylidene-3-O-(2',6'-dimethylbenzyl)-5-deoxy-5-C-propyl-a-D-xylofuranose;

1,2-O-ethylidene-3-O-(2',6'-dimethylbenzyl)-5-deoxy-5-C-propyl-a-D-xylofuranose;

1,2-O-(1-methylpropylidene)-3-O-(2',6'-dimethylbenzyl)-5-deoxy-5-C-propyl-a-D-xylofuranose;

1,2-O-(1-propylpentylidene)-3-O-(2',6'-dimethylbenzyl)-5-deoxy-5-C-propyl-a-D-xylofuranose;

1,2-O-(1,2-dimethylpropylidene)-3-O-(2',6'-dimethylbenzyl)-5-deoxy-5-C-propyl-a-D-xylofuranose;

1,2-O-isopropylidene-3-O-(2',6'-dimethylbenzyl)-5-deoxy-5-C-isopropyl-a-D-xylofuranose;

1,2-O-ethylidene-3-O-(2',6'-dimethylbenzyl)-5-deoxy-5-C-isopropyl-a-D-xylofuranose;

1,2-O-(1-methylpropylidene)-3-O-(2',6'-dimethylbenzyl)-5-deoxy-5-C-isopropyl-a-D-xylofuranose;

1,2-O-(1-propylpentylidene)-3-O-(2',6'-dimethylbenzyl)-5-deoxy-5-C-isopropyl-a-D-xylofuranose;

1,2-O-(1,2-dimethylpropylidene)-3-O-(2',6'-dimethylbenzyl)-5-deoxy-5-C-isopropyl-a-D-xylofuranose;

1,2-O-isopropylidene-3-O-(2'-methoxybenzyl)-5-deoxy-5-C-ethyl-a-D-xylofuranose;

1,2-O-ethylidene-3-O-(2'-methoxybenzyl)-5-deoxy-5-C-ethyl-a-D-xylofuranose;

1,2-O-(1-methylpropylidene)-3-O-(2'-methoxybenzyl)-5-deoxy-5-C-ethyl-a-D-xylofuranose;

1,2-O-(1-propylpentylidene)-3-O-(2'-methoxybenzyl)-5-deoxy-5-C-ethyl-a-D-xylofuranose;and

1,2-O-(1,2-dimethylpropylidene)-3-O-(2'-methoxybenzyl)-5-deoxy-5-C-ethyl-a-D-xylofuranose;

1,2-O-isopropylidene-3-O-(2'-methoxybenzyl)-5-deoxy-5-C-methyl-a-D-xylofuranose;

1,2-O-ethylidene-3-O-(2'-methoxybenzyl)-5-deoxy-5-C-methyl-a-D-xylofuranose;

1,2-O-(1-methylpropylidene)-3-O-(2'-methoxybenzyl)-5-deoxy-5-C-methyl-a-D-xylofuranose;

1,2-O-(1-propylpentylidene)-3-O-(2'-methoxybenzyl)-5-deoxy-5-C-methyl-a-D-xylofuranose;

1,2-O-(1,2-dimethylpropylidene)-3-O-(2'-methoxybenzyl)-5-deoxy-5-C-methyl-a-D-xylofuranose;

1,2-O-isopropylidene-3-O-(2'-methoxybenzyl)-5-deoxy-5-C-propyl-a-D-xylofuranose;

1,2-O-ethylidene-3-O-(2'-methoxybenzyl)-5-deoxy-5-C-propyl-a-D-xylofuranose;

1,2-O-(1-methylpropylidene)-3-O-(2'-methoxybenzyl)-5-deoxy-5-C-propyl-a-D-xylofuranose;

1,2-O-(1-propylpentylidene)-3-O-(2'-methoxybenzyl)-5-deoxy-5-C-propyl-a-D-xylofuranose;

1,2-O-(1,2-dimethylpropylidene)-3-O-(2'-methoxybenzyl)-5-deoxy-5-C-propyl-a-D-xylofuranose;

1,2-O-isopropylidene-3-O-(2'-methoxybenzyl)-5-deoxy-5-C-isopropyl-a-D-xylofuranose;

1,2-O-ethylidene-3-O-(2'-methoxybenzyl)-5-deoxy-5-C-isopropyl-a-D-xylofuranose;

1,2-O-(1-methylpropylidene)-3-O-(2'-methoxybenzyl)-5-deoxy-5-C-isopropyl-a-D-xylofuranose;

1,2-O-(1-propylpentylidene)-3-O-(2'-methoxybenzyl)-5-deoxy-5-C-isopropyl-a-D-xylofuranose;

1,2-O-(1,2-dimethylpropylidene)-3-O-(2'-methoxybenzyl)-5-deoxy-5-C-isopropyl-a-D-xylofuranose;

1,2-O-isopropylidene-3-O-(2'-naphthamethyl)-5-deoxy-5-C-ethyl-a-D-xylofuranose;

1,2-O-ethylidene-3-O-(2'-naphthamethyl)-5-deoxy-5-C-ethyl-a-D-xylofuranose;

1,2-O-(1-methylpropylidene)-3-O-(2'-naphthamethyl)-5-deoxy-5-C-ethyl-a-D-xylofuranose;

1,2-O-(1-propylpentylidene)-3-O-(2'-naphthamethyl)-5-deoxy-5-C-ethyl-a-D-xylofuranose;and

1,2-O-(1,2-dimethylpropylidene)-3-O-(2'-naphthamethyl)-5-deoxy-5-C-ethyl-a-D-xylofuranose;

1,2-O-isopropylidene-3-O-(2'-naphthamethyl)-5-deoxy-5-C-methyl-a-D-xylofuranose;

1,2-O-ethylidene-3-O-ethylidene-3-O-(2'-naphthamethyl)-5-deoxy-5-C-methyl-a-D-xylofuranose;

1,2-O-(1-methylpropylidene)-3-O-(2'-naphthamethyl)-5-deoxy-5-C-methyl-a-D-xylofuranose;

1,2-O-(1-propylpentylidene)-3-O-(2'-naphthamethyl)-5-deoxy-5-C-methyl-a-D-xylofuranose;

1,2-O-(1,2-dimethylpropylidene)-3-O-(2'-naphthamethyl)-5-deoxy-5-C-methyl-a-D-xylofuranose;

1,2-O-isopropylidene-3-O-(2'-naphthamethyl)-5-deoxy-5-C-propyl-a-D-xylofuranose;

1,2-O-ethylidene-3-O-(2'-naphthamethyl)-5-deoxy-5-C-propyl-a-D-xylofuranose;

1,2-O-(1-methylpropylidene)-3-O-(2'-naphthamethyl)-5-deoxy-5-C-propyl-a-D-xylofuranose;

1,2-O-(1-propylpentylidene)-3-O-(2'-naphthamethyl)-5-deoxy-5-C-propyl-a-xylofuranose;

1,2-O-(1,2-dimethylpropylidene)-3-O-(2'-naphthamethyl)-5-deoxy-5-C-propyl-a-D-xylofuranose;

1,2-O-isopropylidene-3-O-(2'-naphthamethyl)-5-deoxy-5-C-isopropyl-a-D-xylofuranose;

1,2-O-ethylidene-3-O-(2'-naphthamethyl)-5-deoxy-5-C-isopropyl-a-D-xylofuranose;

1,2-O-(1-methylpropylidene)-3-O-(2'-naphthamethyl)-5-deoxy-5-C-isopropyl-a-D-xylofuranose;

1,2-O-(1-propylpentylidene)-3-O-(2'-naphthamethyl)-5-deoxy-5-C-isopropyl-a-D-xylofuranose;

1,2-O-(1,2-dimethylpropylidene)-3-O-(2'-naphthamethyl)-5-deoxy-5-C-isopropyl-a-D-xylofuranose.

Similarly, by following the same procedure but respectively replacingbenzyl bromide with 2-methylbenzyl bromide; 3-methylbenzyl bromide;2,6-dichlorobenzyl bromide; 2,3,4,6-tetrafluorobenzyl bromide;2-bromo-4-methylbenzyl bromide; 2,3-dimethyl-4-methoxybenzyl bromide;2,4-dimethylbenzyl bromide; 2,5-dimethylbenzyl bromide;2,4-dibutylbenzyl bromide; 3,4-diethoxybenzyl bromide;2-chloro-4-iodobenzyl bromide, 2-methyl-5-methoxybenzyl bromide and6-methyl-2-naphthamethyl bromide, the corresponding 2-methylbenzyl;3-methyl bromide, the corresponding 2-methylbenzyl; 3-methylbenzyl;2,6-dichlorobenzyl; 2,3,4,6-tetrafluorobenzyl; 2-bromo-4-methyl benzyl;2,3-dimethyl-4-methoxybenzyl; 2,4-dimethylbenzyl; 2,5-dimethylbenzyl;2,4-dibutylbenzyl; 3,4-diethoxybenzyl; 2-chloro-4-iodobenzyl;2-methyl-5-ethoxybenzyl; and 6-ethyl-2-naphthamethyl analogs of each ofthe above compounds can be respectively prepared.

EXAMPLE 5 1,2-O-isopropylidene-5-deoxy-5-iodo-a-D-xylofuranose

In this example 25 g (170 mmoles) of sodium iodide was added to asolution containing 34 g of1,2-O-isopropylidene-5-O-tosyl-a-D-xylofuranose dissolved in 250 ml ofmethyl ethyl ketone and then refluxed, with stirring, for 24 hours. Thereaction mixture was allowed to cool and then filtered. The filtrate wasthen evaporated affording an oil concentrate which was then dissolved in150 ml of chloroform and then washed with 100 ml of aqueous sodiumthiosulfate solution and then washed three times with 150 ml of water.The chloroform layer was dried over anhydrous magnesium sulfate and thenevaporated under vacuum affording the title compound which wascrystallized from ether-hexane, m.p. 102°-105° C.

Similarly, by following the same procedure using the correspondingproducts prepared in Example 2, the following compounds can berespectively prepared:

1,2-O-ethylidene-5-deoxy-5-iodo-a-D-xylofuranose;

1,2-O-(1-methylpropylidene)-5-deoxy-5-iodo-a-D-xylofuranose;

1,2-O-(1-propylpentylidene)-5-deoxy-5-iodo-a-D-xylofuranose; and

1,2-O-(1,2-dimethylpropylidene)-5-deoxy-5-iodo-a-D-xylofuranose.

EXAMPLE 6 1,2-O-isopropylidene-5-deoxy-a-D-xylofuranose

In this example, a reaction mixture containing 2.0 g (10 mmoles) of1,2-O-isopropylidene-5-deoxy-5-iodo-a-D-xylofuranose, 1.5 g (15 mmoles)of triethylamine and 0.1 g of platinum oxide in 30 ml of methanol washydrogenated at room temperature under a hydrogen pressure of 10 psig.Hydrogenation was continued until no further absorption of hydrogen wasobserved (approximately 1 hour). The reaction mixture was then filteredthrough diatomaceous earth. The resulting filtrate was evaporatedaffording the title compound as an off-white solid. This solid was thenrecrystallized from a mixture of ethyl ether and hexane.

Similarly by following the same procedure but respectively using theproducts of Example 5 as starting materials, the following compounds canbe respectively prepared:

1,2-O-ethylidene-5-deoxy-a-D-xylofuranose;

1,2-O-(1-methylpropylidene)-5-deoxy-a-D-xylofuranose;

1,2-O-(1-propylpentylidene)-5-deoxy-a-D-xylofuranose; and

1,2-O-(1,2-dimethylpropylidene)-5-deoxy-a-D-xylofuranose.

EXAMPLE 7 1,2-O-isopropylidene-3-O-benzyl-5-deoxy-a-D-xylofuranose

In this example, 1.15 g (0.024 moles) of sodium hydride, in the form ofa 50 wt. % mixture with mineral oil, was slowly added under a nitrogenatmosphere to a solution containing 3.5 g of1,2-O-isopropylidene-5-deoxy-a-D-xylofuranose in 20 ml oftetrahydrofuran at room temperature. After 15 minutes, 0.3 g oftetrabutyl ammonium iodide and 4.1 g (0.024 moles) of benzyl bromidewere added. The resulting mixture was stirred overnight at roomtemperature. The reaction mixture was then concentrated by evaporationunder reduced pressure. 100 ml of water and 100 ml of methylene chloridewere then added to the concentrate. The organic layer was separated andwashed twice with water and dried by using anhydrous magnesium sulfateand concentrated by evaporation affording a yellow liquid. This liquidwas then dissolved in 100 ml of acetonitrile and washed twice with 15 mlof hexane to remove mineral oil. The acetonitrile layer was separatedand evaporated affording a liquid which was then distilled at 132°-135°C. and 0.5 mm Hg affording 3.6 g of the title compound as a colorlessliquid.

Similarly, by following the same procedure using the correspondingproducts of Example 6 as starting materials, the following compounds canbe respectively prepared:

1,2-O-ethylidene-3-O-benzyl-5-deoxy-a-D-xylofuranose;

1,2-O-(1-methylpropylidene)-3-O-benzyl-5-deoxy-a-D-xylofuranose;

1,2-O-(1-propylpentylidene)-3-O-benzyl-5-deoxy-a-D-xylofuranose; and

1,2-O-(1,2-dimethylpropylidene)-3-O-benzyl-5-deoxy-a-D-xylofuranose.

Similarly, by following the same procedure but using 2-chlorobenzylbromide in place of benzyl bromide the following compounds can berespectively prepared:

1,2-O-isopropylidene-3-O-(2'-chlorobenzyl)-5-deoxy-a-D-xylofuranose;

1,2-O-methylene-3-O-(2'-chlorobenzyl)-5-deoxy-a-D-xylofuranose;

1,2-O-ethylidene-3-O-(2'-chlorobenzyl)-5-deoxy-a-D-xylofuranose;

1,2-O-(1-methylpropylidene)-3-O-(2'-chlorobenzyl)-5-deoxy-a-D-xylofuranose;

1,2-O-(1-propylpentylidene)-3-O-(2'-chlorobenzyl)-5-deoxy-a-D-xylofuranose;and

1,2-O-(1,2-dimethylpropylidene)-3-O-(2'-chlorobenzyl)-5-deoxy-a-D-xylofuranose.

Similarly, by following the same procedure but using 2-fluorobenzylbromide in place of benzyl bromide the following compounds can berespectively prepared:

1,2-O-isopropylidene-3-O-(2'-fluorobenzyl)-5-deoxy-a-D-xylofuranose;

1,2-O-methylene-3-O-(2'-fluorobenzyl)-5-deoxy-a-D-xylofuranose;

1,2-O-ethylidene-3-O-(2'-fluorobenzyl)-5-deoxy-a-D-xylofuranose;

1,2-O-(1-methylpropylidene)-3-O-(2'-fluorobenzyl)-5-deoxy-a-D-xylofuranose;

1,2-O-(1-propylpentylidene)-3-O-(2'-fluorobenzyl)-5-deoxy-a-D-xylofuranose;and

1,2-O-(1,2-dimethylpropylidene)-3-O-(2'-fluorobenzyl)-5-deoxy-a-D-xylofuranose.

Similarly, by following the same procedure but respectively replacingbenzyl bromide with 2-methylbenzyl bromide; 3-methylbenzyl bromide;2,6-dichlorobenzyl bromide; 2,3,4,6-tetrafluorobenzyl bromide;2-bromo-4-methylbenzyl bromide; 2,3-dimethyl-4-methoxybenzyl bromide;2,4-dimethylbenzyl bromide; 2,5-dimethylbenzyl bromide;2,4-dibutylbenzyl bromide; 3,4-diethoxybenzyl bromide;2-chloro-4-iodobenzyl bromide and 2-methyl-5-methoxybenzyl bromide and6-ethyl-2-naphthamethyl bromide, the corresponding 2-methylbenzyl;3-methylbenzyl; 2,6-dichlorobenzyl; 2,3,4,6-tetrafluorobenzyl;2-bromo-4-methyl benzyl; 2,3-dimethyl-4-methoxybenzyl;2,4-dimethylbenzyl; 2,5-dimethylbenzyl; 2,4-dibutylbenzyl;3,4-diethoxybenzyl; 2-chloro-4-iodobenzyl; 2-methyl-5-ethoxybenzyl; and6-ethyl-2-naphthamethyl analogs of each of the above compounds arerespectively prepared.

EXAMPLE 8 1,2:5,6-di-O-isopropylidene-a-D-glucofuranose

In this example, 125 g of powdered D-glucose is added to a stirredsolution of 120 ml of concentrated 96 wt.% sulfuric acid in 3 liters ofacetone and the mixture is stirred vigorously at room temperatureovernight. The reaction mixture is cooled to 10° C. and gaseous ammoniais bubbled keeping the temperature below 25° C. Solids are filtered offand the filtrate is concentrated under reduced pressure. The residue istreated with 1 liter of water and extracted three times with 300 ml ofmethylene chloride. The methylene chloride extracts are combined, washedwith water, dried with anhydrous magnesium sulfate, and concentrated togive a white crystalline residue of crude1,2:5,6-di-O-isopropylidene-a-D-glucofuranose.

Similarly, by following the same procedure but using the correspondingketone in place of acetone, the following compounds can be respectivelyprepared:

1,2:5,6-di-O-(1-methylpropylidene)-a-D-glucofuranose;

1,2:5,6-di-O-(1-ethylpropylidene)-a-D-glucofuranose; and

1,2:5,6-di-O-(1-propylbutylidene)-a-D-glucofuranose.

EXAMPLE 91,2:5,6-di-O-isopropylidene-3-O-(2'-chlorobenzyl)-a-D-glucofuranose

In this example 4.9 g (0.1 moles) of sodium hydride in the form of a 50wt. % mixture with mineral oil was slowly added under an atmosphere ofnitrogen to a cooled solution containing 26 g of1,2:5,6-di-O-isopropylidene-a-D-glucofuranose in 75 ml oftetrahydrofuran. 2 g of benzyl triethyl ammonium chloride was then addedto this mixture and then 16.1 g (0.1 moles) of 2-chlorobenzyl chloridewas added. The reaction mixture was then stirred overnight (about 12hours) at room temperature. The reaction mixture was concentrated byevaporation under reduced pressure affording a viscous mixture which wasthen dissolved in 200 ml of petroleum ether and washed three times with100 ml water, then dried over anhydrous magnesium sulfate and evaporatedunder vacuum. The resulting liquid residue was distilled under vacuum toremove unreacted 2-chlorobenzyl chloride affording the title compound asa liquid.

Similarly, by following the same procedure by respectively using theother products of Example 8 as starting materials, the followingcompounds can be respectively prepared:

1,2:5,6-di-O-(1-methylpropylidene)-3-O-(2'-chlorobenzyl)-a-D-glucofuranose;

1,2:5,6-di-O-(1-ethylpropylidene)-3-O-(2'-chlorobenzyl)-a-D-glucofuranose;and

1,2:5,6-di-O-(1-propylbutylidene)-3-O-(2'-chlorobenzyl)-a-D-glucofuranose.

Similarly, by following the same procedure but respectively using benzylchloride; 2-fluorobenzyl chloride; 3-hexylbenzyl chloride;3-bromobenzylchloride; 4-methoxybenzyl chloride; 2-fluoro-4-methylbenzylchloride; and 2,3,4,5-tetramethylbenzyl chloride, the followingcompounds can be respectively prepared:

1,2:5,6-di-O-isopropylidene-3-O-benzyl-a-D-glucofuranose;

1,2:5,6-di-O-(1-methylpropylidene)-3-O-benzyl-a-D-glucofuranose;

1,2:5,6-di-O-(1-ethylpropylidene)-3-O-benzyl-a-D-glucofuranose; and

1,2:5,6-di-O-(1-propylbutylidene)-3-O-benzyl-a-D-glucofuranose;

1,2:5,6-di-O-isopropylidene-3-O-(2'-fluorobenzyl)-a-D-glucofuranose;

1,2:5,6-di-O-(1-methylpropylidene)-3-O-(2'-fluorobenzyl)-a-D-glucofuranose;

1,2:5,6-di-O-(1-ethylpropylidene)-3-O-(2'-fluorobenzyl)-a-D-glucofuranose;and

1,2:5,6-di-O-(1-propylbutylidene)-3-O-(2'-fluorobenzyl)-a-D-glucofuranose;

1,2:5,6-di-O-isopropylidene-3-O-(3'-hexylbenzyl)-a-D-glucofuranose;

1,2:5,6-di-O-(1-methylpropylidene)-3-O-(3'-hexylbenzyl)-a-D-glucofuranose;

1,2:5,6-di-O-(1-ethylpropylidene)-3-O-(3'-hexylbenzyl)-a-D-glucofuranose;and

1,2:5,6-di-O-(1-propylbutylidene)-3-O-(3'-hexylbenzyl)-a-D-glucofuranose;

1,2:5,6-di-O-isopropylidene-3-O-(2'-bromobenzyl)-a-D-glucofuranose;

1,2:5,6-di-O-(1-methylpropylidene)-3-O-(2'-bromobenzyl)-a-D-glucofuranose;

1,2:5,6-di-O-(1-ethylpropylidene)-3-O-(2'-bromobenzyl)-a-D-glucofuranose;and

1,2:5,6-di-O-(1-propylbutylidene)-3-O-(2'-bromobenzyl)-a-D-glucofuranose;

1,2:5,6-di-O-isopropylidene-3-O-(4'-methoxybenzyl)-a-D-glucofuranose;

1,2:5,6-di-O-(1-methylpropylidene)-3-O-(4'-methoxybenzyl)-a-D-glucofuranose;

1,2:5,6-di-O-(1-ethylpropylidene)-3-O-(4'-methoxybenzyl)-a-D-glucofuranose;

1,2:5,6-di-O-(1-propylbutylidene)-3-O-(4'-methoxybenzyl)-a-D-glucofuranose;

1,2:5,6-di-O-(isopropylidene)-3-O-(2'-fluoro-4'-methylbenzyl)-a-D-glucofuranose;

1,2:5,6-di-O-(1-methylpropylidene)-3-O-(2'-fluoro-4'-methylbenzyl)-a-D-glucofuranose;

1,2:5,6-di-O-(1-ethylpropylidene)-3-O-(2'-fluoro-4'-methylbenzyl)-a-D-glucofuranose;

1,2:5,6-di-O-(1-propylbutylidene)-3-O-(2'-fluoro-4'-methylbenzyl)-a-D-glucofuranose;

1,2:5,6-di-O-isopropylidene-3-O-(2'3'4'5'tetramethylbenzyl)-a-D-glucofuranose;

1,2:5,6-di-O-(1-methylpropylidene)-3-O-(2'3'4'5'tetramethylbenzyl)-a-D-glucofuranose;

1,2:5,6-di-O-(1-ethylpropylidene)-3-O-(2'3'4'5'tetramethylbenzyl)-a-D-glucofuranose;and

1,2:5,6-di-O-(1-propylbutylidene)-3-O-(2'3'4'5'tetramethylbenzyl)-a-D-glucofuranose.

EXAMPLE 10 1,2-O-isopropylidene-3-O-(2'-chlorobenzyl)-a-D-glucofuranose

In this example 167.9 g of1,2:5,6-di-O-isopropylidene-3-O-(2'-chlorobenzyl)-a-D-glucofuranose wasstirred in a mixture of 495 ml of acetic acid and 275 ml of water at40°-45° C. for about 12 hours. The reaction was monitored by thin layerchromatography. The reaction mixture was then cooled to room temperatureand the acetic acid was then carefully neutralized by the slow additionof an aqueous saturated potassium carbonate solution and then extractedthree times with 500 ml of methylene chloride. The extracts werecombined and then washed twice with water and then with a saturatedsodium chloride solution. The washed extracts were then dried overmagnesium sulfate and evaporated under reduced pressure affording thetitle compound as a straw colored syrup.

Similarly, by following the same procedure, the 5,6-isopropylidenemoieties are selectively hydrolyzed from the products of Example 9.

EXAMPLE 111,2-O-isopropylidene-3-O-(2'-chlorobenzyl)-5-deoxy-5-C-methylene-a-D-xylofuranose

In this example 36 g (0.24 mol) of triethylorthoformate and 2 mls ofglacial acid was added to 37.6 g (0.109 mol) of1,2-O-isopropylidene-3-O-(2'-chlorobenzyl)-a-D-glucofuranose. Theresulting mixture was refluxed for six hours. Excesstriethylorthoformate was then removed by evaporation at 0.5 mm Hg. Theresulting residue was then mixed three times with 100 mls of toluenefollowed by evaporation after each mixing to remove any traces ofsolvent affording 45.3 g of1,2-O-isopropylidene-3-O-(2'-chlorobenzyl)-5,6-O-(ethoxymethylene)-a-D-glucofuranoseas a yellow syrup.

45 g of this product was then mixed with 0.5 g triphenyl acetic acid andthen heated at 170° C. (0.5 mm Hg) for 6 hours to distill off theethanol byproduct of the reaction. The resulting syrup was then dilutedwith 300 ml of ethyl ether and then neutralized by the addition ofsodium bicarbonate. The mixture was vigorously stirred and filtered. Theresulting filtrate was washed twice with aqueous sodium bicarbonate,dried over magnesium sulfate and then evaporated. The resulting residuewas distilled at 175°-178° C., 1.2 mm Hg yielding the title compound asa yellow syrup.

Similarly, by following the same procedure, using the correspondingproducts of Example 10 as starting materials, the following compoundsare respectively prepared:

1,2-O-(1-methylpropylidene)-3-O-(2'-chlorobenzyl)-5-deoxy-5-C-methylene-a-D-xylofuranose;

1,2-O-(1-ethylpropylidene)-3-O-(2'-chlorobenzyl)-5-deoxy-5-C-methylene-a-D-xylofuranose;and

1,2-O-(1-propylbutylidene)-3-O-(2'-chlorobenzyl)-5-deoxy-5-C-methylene-a-D-xylofuranose.

EXAMPLE 121,2-O-isopropylidene-3-O-benzyl-5-deoxy-5-C-methylmethylene-a-D-xylofuranose(R is CH₃ CH═CH-)

The title compound can be prepared by the following procedure: 3.7 g(0.01 mol) of triphenylethyl phosphonium bromide is added in portions toa solution of 0.01 mol of n-butyllithium in 100 ml of tetrahydrofuranwith stirring under nitrogen. After stirring for 4 hours at roomtemperature, 2.8 g (0.01 mol) of3-O-benzyl-1,2-O-isopropylidene-a-D-xylo-pentodialdo-1,4-furanose[Carbohydrate Research 14, 159-171 (1970)] dissolved in 20 ml oftetrahydrofuran is added dropwise and stirred overnight. The solventsare evaporated and the residue is treated with hexane-ethyl ether toprecipitate solids. After filtration, the filtrate is concentrated underreduced pressure and purified by flash column chromatography employingtetrahydrofuran-hexane (1:4 by volume) as eluent to afford the titlecompound.

EXAMPLE 12a1,2-O-isopropylidene-3-O-benzyl-5-deoxy-5-C-vinylmethyl-a-D-xylofuranose(R is CH₂ ═CH-CH₂ -)

The title compound can be prepared by the following procedure: treatmentof 3.6 g (0.01 mol) of triphenylmethyl phosphonium bromide with 2.9 g(0.01 mol) of3-O-benzyl-5-deoxy-1,2-O-isopropylidene-a-D-xylo-hexodialdo-1,4-furanose[Helv. Chim. Acta 63, 1644 (1980)] in a similar manner as described inExample 12 will afford the title compound.

EXAMPLE 12b1,2-O-isopropylidene-3-O-benzyl-5-deoxy-5-C-dimethyl-a-D-xylofuranose (Ris isopropyl)

The title compound can be prepared by the following procedure: 3.6 g(0.01 mol) of triphenylmethylphosphonium bromide is reacted with 3.0 g(0.01 mol) of3-O-benzyl-6-deoxy-1,2-O-isopropylidene-a-D-xylo-hexofuranos-5-ulose[Carbohydrate Research, 31, 387-396 (1973)] in the same manner asdescribed in Example 12 and hydrogenated at 20 psi of hydrogen pressureemploying 0.5 g of 5 wt. % palladium on charcoal catalyst as describedin Example 15 to afford the title compound.

EXAMPLE 131,2-O-methylidene-3-O-benzyl-5-deoxy-5-C-methylene-a-D-xylofuranose

In this example, a mixture containing 5.5 g (0.02 mol) of1,2-O-isopropylidene-3-O-benzyl-5-deoxy-5-C-methylene-a-D-xylofuranose,10 g of paraformaldehyde in 35 mls of glacial acetic acid was heated at70°-80° C. for 15 minutes. 2.75 g of concentrated sulfuric acid was thenadded and the mixture then heated at 70°-80° C. for an additional twohours. The mixture is cooled and then water added. The mixture was thenextracted with methylene chloride. The combined extracts were washedwith water, quenched with solid sodium bicarbonate and then washed withwater until neutral. The neutralized mixture was dried over magnesiumsulfate, evaporated, and then distilled at 150°-184° C. at 1 mm of Hg.The residue was then chromatographed on silica gel eluting withtetrahydrofurane-hexane mixtures (1:4 by volume). The entire procedurewas repeated twice more affording 4.2 g of the title product as acolorless liquid.

Similarly, by following the same procedure using the1,2-O-isopropylidene products of Examples 4, 7 and 11 as startingmaterials, the corresponding 1,2-O-methylidene homologs of theseproducts are prepared.

Similarly, by following a similar procedure but using acetaldehyde inplace of paraformaldehyde, the corresponding 1,2-O-ethylidene homologsof each of the 1,2-O-methylidene products are respectively prepared.

EXAMPLE 141,2-O-(1-ethylpropylidene)-3-O-benzyl-5-deoxy-5-C-methyl-a-D-xylofuranose

In this example a mixture containing 5.6 (0.02 mol) of1,2-O-isopropylidene-3-O-benzyl-5-deoxy-5-C-methyl-a-D-xylofuranose in40 mls of a mixture of trifluoroacetic acid and water containing 9 partsby volume of trifluoroacetic acid per part of water was stirred for onehour at room temperature. The solvents were then removed by rotaryevaporation at 50°-55° C. The resulting residue was mixed with 30 mls ofpentanone, 0.5 ml of concentrated sulfuric acid and 5 g of anhydrouscopper sulfate. This mixture was stirred overnight (about 12-15 hours)at room temperature. Examination by thin layer chromatography showedcompletion of the reaction. Powdered anhydrous sodium carbonate was thenadded and stirred followed by the addition of 200 mls of ethyl ether andthen saturated aqueous sodium bicarbonate. The ethyl ether layer wasseparated, washed with water until neutral and then dried over anhydrousmagnesium sulfate and concentrated by vacuum evaporation. Theconcentrate was flash column chromatographed eluting withtetrahydrofuranhexane mixtures (1:6 by volume) affording 3.2 g of thetitle compound as a colorless liquid.

Similarly, by following the same procedure using the1,2-O-isopropylidene or other 1,2-O-alkylidene products of Examples 4, 7and 11 as starting materials the corresponding1,2-O-(1-ethylpropylidene) homologs of each of those products arerespectively prepared.

Similarly, by following the same procedure but using other aldehydes orketones in place of pentanone, the corresponding 1,2-O-alkylidene or1,2-O-(1-substituted-alkylidene) homologs are prepared.

EXAMPLE 151,2-O-isopropylidene-3-O-(2'-chlorobenzyl)-5-deoxy-5-C-methyl-a-D-xylofuranose

In this example 6 g of1,2-O-isopropylidene-3-O-(2'-chlorobenzyl)-5-deoxy-5-C-methylene-a-D-xylofuranosewere dissolved in 150 mls of ethanol and then 1.5 g of 5 wt. % palladiumon charcoal catalyst is added. This mixture was then hydrogenated at 20psig of hydrogen pressure for 20 minutes. The mixture was then filteredthrough diatomaceous earth, then evaporated affording a solid. Thissolid was then dissolved in 100 ml of methylene chloride, then washedwith water and dried over magnesium sulfate and evaporated under vacuum.The residue was then recrystallized from a mixture of ethanol and wateraffording 3.6 g of the title compound as a white powder m.p. 68°-69° C.

Similarly, by following the same procedure, portions of the products ofExamples 11, 12, and 13 are respectively hydrogenated to thecorresponding saturated alkyl compound.

EXAMPLE 16

By applying the appropriate procedures described in the above examplesand the appropriate starting materials, the compounds listed in Table Ahereinbelow were prepared.

                                      TABLE A                                     __________________________________________________________________________     ##STR10##                                                                                                   ELEMENTAL ANALYSIS                                                            Carbon Hydrogen                                                                             Nitrogen                         No. R        R.sup.1 R.sup.2                                                                            R.sup.3                                                                            Calc.                                                                            Found                                                                             Calc.                                                                            Found                                                                             Calc.                                                                            Found                         __________________________________________________________________________    1   CH.sub.3 φ*  CH.sub.3                                                                           CH.sub.3                                                                           68.16                                                                            68.14                                                                             7.63                                                                             7.90                                                                              0  0.09                          2   CH.sub.2 CH.sub.3                                                                      φ   CH.sub.3                                                                           CH.sub.3                                                                           69.04                                                                            67.90                                                                             7.97                                                                             7.90                                                                              0  0.34                          3   CH.sub.2 CH.sub.3                                                                      2-Clφ                                                                             CH.sub.3                                                                           CH.sub.3                                                                           61.44                                                                            63.11                                                                             6.77                                                                             7.12                                                                              0  0.09                          4   CH.sub.2 CH.sub.3                                                                      2-Fφ                                                                              CH.sub.3                                                                           CH.sub.3                                                                           64.85                                                                            63.75                                                                             7.14                                                                             7.27                                                                              -- --                            5   CH.sub.2 CH.sub.3                                                                      2-CH.sub.3φ                                                                       CH.sub.3                                                                           CH.sub.3                                                                           69.84                                                                            71.33                                                                             8.27                                                                             9.06                                                                              -- --                            6   CH.sub.2 CH.sub.3                                                                      2-Cl6-Clφ                                                                         CH.sub.3                                                                           CH.sub.3                                                                           55.34                                                                            56.34                                                                             5.81                                                                             6.15                                                                              0  0.01                          7   CH.sub.2 CH.sub.2 CH.sub.3                                                             φ   CH.sub.3                                                                           CH.sub.3                                                                           69.84                                                                            69.90                                                                             8.27                                                                             8.70                                                                              0  0.04                          8   CH.sub.2 (CH.sub.2).sub.2 CH.sub.3                                                     φ   CH.sub.3                                                                           CH.sub.3                                                                           70.56                                                                            71.05                                                                             8.55                                                                             8.30                                                                              0  0.57                          9   CHCH.sub.2                                                                             φ   CH.sub.3                                                                           CH.sub.3                                                                           69.54                                                                            68.90                                                                             7.29                                                                             7.71                                                                              0  0.22                          10  CHCH.sub.2                                                                             2-Clφ                                                                             CH.sub.3                                                                           CH.sub.3                                                                           61.84                                                                            64.19                                                                             6.16                                                                             6.48                                                                              0  0.08                          11  CHCH.sub.2                                                                             2-Fφ                                                                              CH.sub.3                                                                           CH.sub.3                                                                           65.29                                                                            68.58                                                                             6.51                                                                             7.11                                                                              -- --                            12  CHCH.sub.2                                                                             2-CH.sub.3φ                                                                       CH.sub.3                                                                           CH.sub.3                                                                           70.32                                                                            73.65                                                                             6.60                                                                             8.03                                                                              -- --                            13  CHCH.sub.2                                                                             2-Cl6-Clφ                                                                         CH.sub.3                                                                           CH.sub.3                                                                           55.67                                                                            56.36                                                                             5.26                                                                             5.52                                                                              0  0.06                          14  CH.sub.2 CH.sub.3                                                                      φ   H    H    67.18                                                                            67.65                                                                             7.25                                                                             7.60                                                                              0  0.02                          15  CH.sub.2 CH.sub.3                                                                      φ   CH.sub.3 CH.sub.2                                                                  CH.sub.3 CH.sub.2                                                                  70.56                                                                            71.60                                                                             8.55                                                                             8.98                                                                              0  0.42                          16  CHCH.sub.2                                                                             φ   H    H    67.73                                                                            67.38                                                                             6.50                                                                             6.82                                                                              0  0.01                          17  CHCH.sub.2                                                                             φ   CH.sub.3 CH.sub.2                                                                  CH.sub.3 CH.sub.2                                                                  71.03                                                                            70.96                                                                             7.95                                                                             7.84                                                                              0  0.03                          18  CHCH.sub.2                                                                             4-Fφ                                                                              CH.sub.3                                                                           CH.sub.3                                                                           65.29                                                                            65.45                                                                             6.51                                                                             6.67                                                                              -- --                            19  CH.sub.2 CH.sub.3                                                                      4-Fφ                                                                              CH.sub.3                                                                           CH.sub.3                                                                           64.85                                                                            65.65                                                                             7.14                                                                             7.42                                                                              -- --                            20  CHCH.sub.2                                                                             3-Clφ                                                                             CH.sub.3                                                                           CH.sub.3                                                                           61.43                                                                            62.15                                                                             6.77                                                                             6.91                                                                              -- --                            21  CHCH.sub.2                                                                             4-Clφ                                                                             CH.sub.3                                                                           CH.sub.3                                                                           61.83                                                                            62.25                                                                             6.16                                                                             6.36                                                                              -- --                            22  CH.sub.2 CH.sub.3                                                                      4-Clφ                                                                             CH.sub.3                                                                           CH.sub.3                                                                           61.43                                                                            62.51                                                                             6.77                                                                             7.09                                                                              -- --                            23C**                                                                             CHCH.sub.2                                                                             2,4-Cl.sub.2φ                                                                     CH.sub.3                                                                           CH.sub.3                                                                           55.66                                                                            56.14                                                                             5.25                                                                             5.43                                                                              -- --                            24  CH.sub.2 CH.sub.3                                                                      2,4-Cl.sub.2φ                                                                     CH.sub.3                                                                           CH.sub.3                                                                           55.34                                                                            56.09                                                                             5.81                                                                             6.10                                                                              -- --                            25C CHCH.sub.2                                                                             3,4-Cl.sub.2φ                                                                     CH.sub.3                                                                           CH.sub.3                                                                           55.66                                                                            56.57                                                                             5.25                                                                             6.22                                                                              -- --                            26  CH.sub.2 CH.sub.3                                                                      3,4-Cl.sub.2φ                                                                     CH.sub.3                                                                           CH.sub.3                                                                           55.34                                                                            55.46                                                                             5.81                                                                             6.60                                                                              -- --                            27  CHCH.sub.2                                                                             3-CH.sub.3φ                                                                       CH.sub.3                                                                           CH.sub.3                                                                           70.32                                                                            69.62                                                                             7.64                                                                             8.72                                                                              -- --                            28  CH.sub.2 CH.sub.3                                                                      3-CH.sub.3φ                                                                       CH.sub.3                                                                           CH.sub.3                                                                           69.84                                                                            69.04                                                                             8.27                                                                             8.38                                                                              -- --                            29  CHCH.sub.2                                                                             4-CH.sub.3φ                                                                       CH.sub.3                                                                           CH.sub.3                                                                           70.32                                                                            72.37                                                                             7.64                                                                             8.06                                                                              -- --                            30  CH.sub.2 CH.sub.3                                                                      4-CH.sub.3φ                                                                       CH.sub.3                                                                           CH.sub.3                                                                           69.84                                                                            69.62                                                                             8.27                                                                             8.48                                                                              0  0.68                          31C**                                                                             CHCH.sub.2                                                                             3-CF.sub.3φ                                                                       CH.sub.3                                                                           CH.sub.3                                                                           59.30                                                                            59.64                                                                             5.56                                                                             5.80                                                                              -- --                            32C CH.sub.2 CH.sub.3                                                                      3-CF.sub.3φ                                                                       CH.sub.3                                                                           CH.sub.3                                                                           58.95                                                                            60.12                                                                             6.11                                                                             6.59                                                                              0  0.64                          33  CHCH.sub.2                                                                             2-OCH.sub.3φ                                                                      CH.sub.3                                                                           CH.sub.3                                                                           66.65                                                                            67.19                                                                             7.24                                                                             7.63                                                                              -- --                            34  CH.sub.2 CH.sub.3                                                                      2-OCH.sub.3φ                                                                      CH.sub.3                                                                           CH.sub.3                                                                           66.21                                                                            66.25                                                                             7.84                                                                             8.15                                                                              -- --                            35  CHCH.sub.2                                                                             4-OCH.sub.3φ                                                                      CH.sub.3                                                                           CH.sub.3                                                                           66.65                                                                            67.53                                                                             7.24                                                                             7.84                                                                              -- --                            36  CH.sub.2 CH.sub.3                                                                      4-OCH.sub.3φ                                                                      CH.sub.3                                                                           CH.sub.3                                                                           66.21                                                                            66.74                                                                             7.84                                                                             8.24                                                                              -- --                            37  CH.sub.3 2-Clφ                                                                             CH.sub.3                                                                           CH.sub.3                                                                           60.30                                                                            60.36                                                                             6.41                                                                             6.61                                                                              0  0.05                          38  CH.sub.2 CH.sub.2 CH.sub.3                                                             2-Clφ                                                                             CH.sub.3                                                                           CH.sub.3                                                                           62.48                                                                            61.56                                                                             7.09                                                                             7.33                                                                              0  0.02                          39  CH.sub.2 CH.sub.3                                                                      1-naphthyl                                                                            CH.sub.3                                                                           CH.sub.3                                                                           73.14                                                                            74.45                                                                             7.37                                                                             7.40                                                                              -- --                            40  CH.sub.2 CH.sub.3                                                                      3-Clφ                                                                             CH.sub.3                                                                           CH.sub.3                                                                           61.43                                                                            62.15                                                                             6.77                                                                             6.91                                                                              -- --                            __________________________________________________________________________     *φ = phenyl-                                                              **Compounds with a "C" number are comparison compounds                   

A number of tetrahydrofuran compounds, including the C-3 epimers ofCompounds 2 and 9 of the present invention, were prepared for thepurposes of conducting comparison by logical activity stage.

                  TABLE B                                                         ______________________________________                                        Comparison Compounds                                                           ##STR11##                                                                     ##STR12##                                                                    For-                                                                          mu-            Elemental Analysis                                             la             Carbon    Hydrogen  Nitrogen                                   No.  R           X.sub.1                                                                             Calc.                                                                              Fd.  Calc.                                                                              Fd.  Calc.                                                                              Fd.                           ______________________________________                                        X-1  CH.sub.2 CH.sub.3                                                                         --    69.04                                                                              70.68                                                                              7.97 8.02 0    0.01                          X-2  CHCH.sub.2  --    69.54                                                                              72.64                                                                              7.29 7.70 0    0.23                          Y-1  CH.sub.2 CH.sub.2 CH.sub.3                                                                --    59.39                                                                              59.79                                                                              8.97 9.32 0    0.01                          Y-2  (CH.sub.2).sub.3 CH.sub.3                                                                 --    61.09                                                                              63.18                                                                              9.32 9.52 0    0.19                          Z-1  --          H     74.13                                                                              74.52                                                                              7.92 8.18 0    0                             Z-2  --          Cl    62.12                                                                              60.86                                                                              6.16 5.84 0    0.28                          D-S  --          --    --   --   --   --   --   --                            ______________________________________                                    

EXAMPLE 17

In this example, the compounds of Table A and the comparison compoundslisted in Table B were repectively tested for pre-emergent andpost-emergent activity against a variety of grasses and broad-leafplants including one grain crop and one broad-leaf crop. The compoundstested are identified in Tables A and B hereinbelow.

Pre-Emergent Herbicide Test

Pre-emergence herbicidal activty was determined in the following manner.

Test solutions of the respective compounds were prepared as follows:

355.5 mg of test compound was dissolved in 15 ml of acetone. 2 ml ofacetone containing 110 mg of a non-ionic surfactant was added to thesolution. 12 ml of this stock solution was then added to 47.7 ml ofwater which contained the same nonionic surfactant at a concentration of625 mg/l.

Seeds of the test vegetation were planted in a pot of soil and the testsolution was sprayed uniformly onto the soil surface at a dose of 27.5micrograms/cm². The pot was watered and placed in a greenhouse. The potwas watered intermittently and observed for seedling emergence, healthof emerging seedlings, etc., for a 3-week period. At the end of thisperiod, the herbicidal effectiveness of the compound was rated based onthe physiological observations. A 0- to 100-scale was used, 0representing no phytotoxicity, 100 representing complete kill. Theresults of these tests are summarized in Table 1.

Post-Emergent Herbicidal Test

The test compound was formulated in the same manner as described abovefor the pre-emergent test. This formulation was uniformly sprayed on 2similar pots containing plants 2 to 3 inches tall (except wild oats,soybean and watergrass which were 3 to 4 inches tall) (approximately 15to 25 plants per pot) at a dose of 27.5 microgram/cm². After the plantshad dried, they were placed in a greenhouse and then wateredintermittently at their bases as needed. The plants were observedperiodically for phytotoxic effects and physiological and morphologicalresponses to the treatment. After 3 weeks, the herbicidal effectivenessof the compound was rated based on these observations. A 0- to 100-scalewas used, 0 representing no phytotoxicity, 100 representing completekill. The results of these tests are summarized in Table 2.

                  TABLE 1                                                         ______________________________________                                        Pre-Emergence Herbicidal Activity                                             Broad-Leaf Plants                                                             % Phytotoxicity    Grasses                                                    Com-  Lambs                % Phytotoxicity                                    pound Quar-   Mus-   Pig- Soy- Crab  Water Wild                               No.   ter     tard   weed bean Grass Grass Oats Rice                          ______________________________________                                         1     0      0      15   0    98    100   80   100                            2    65      25     68   50   100   100   96   100                            3    65      58     45   60   100   100   85   98                             4    65      15     60   35   100   100   99   99                             5    83      38     45   55   100   100   75   100                            6    65      50     45   28   100   100   45   58                             7     0      0       0   0    100   100   93   100                            8    20      0       0   10   93    100   25    0                             9    55      25     60   0    100   100   70   88                            10    55      18      0   0    99     99   35   40                            11    60      13     40   35   100   100   15   60                            12    67      0      25   0    100    99    0   23                            13    55      35     15   23   75     80   20   25                            14    25      0      15   35   100   100    0   90                            15    10      0      30   10   100   100    0   93                            16     0      0       0   0    95    100    0   20                            17    10      0      10   0    100   100    0   25                            18    40      15     45   0    80     80    0   58                            19    60      60     60   25   100   100   90   99                            20*   --      --     --   --   --    --    --   --                            21     0      0      43   35   88     58    0    0                            22    65      20     60   0    100   100   63   60                            23     0      0       0   0     0     0     0    0                            24     0      0       0   0    92     75    0    0                            25     0      0       0   0     0     0     0    0                            26     0      0       0   0    20     55    0    0                            27     0      0       0   0    55     65    0    0                            28    60      15      0   0    99    100   35   60                            29     0      0       0   0    60     75    0    0                            30    50      30     55   35   100   100   30   70                            31     0      0       0   0     0     0     0    0                            32     0      0       0   0     0     0     0    0                            33    63      35     65   0    15    100   63   15                            34    70      18     65   0    75     30   65   40                            35    50      30     60   0    50     0    65    0                            36    50      40     53   10   94     43   63   50                            37     0      0      40   0    100   100   55   60                            38    65      0       0   0    100   100   65   63                            39    52      0       0   20   80     80    0    0                            40    55      0      30   20   99    100   35   30                            X-1    0      0       0   0     0     0     0    0                            X-2    0      0       0   0     0     0     0    0                            Y-1    0      0       0   0     0     0     0    0                            Y-2    0      0       0   0     0     0     0    0                            Z-1   10      0      15   10   98     99   60   100                           Z-2   10      10     10   0    100    98   60   97                            D-S    0      83     55   45   43     40    0   65                            ______________________________________                                         *Not tested                                                              

                  TABLE 2                                                         ______________________________________                                        Post-Emergence Herbicidal Activity                                            Broad-Leaf Plants                                                             % Phytotoxicity    Grasses                                                    Com-  Lambs                % Phytotoxicity                                    pound Quar-   Mus-   Pig- Soy- Crab  Water Wild                               No.   ter     tard   weed bean Grass Grass Oats Rice                          ______________________________________                                         1    0       0      0    0    0     0     0    0                              2    0       0      0    0    45    80    60   10                             3    70      65     60   68   40    65    0    0                              4    50      15     0    55   50    80    60   35                             5    55      40     25   60   20    45    0    0                              6    60      45     38   60   30    65    0    0                              7    0       0      0    0    0     0     0    0                              8    0       0      0    0    0     0     0    0                              9    0       0      0    0    0     0     0    0                             10    15      0      0    55   0     0     0    0                             11    15      0      0    15   0     0     0    0                             12    20      0      0    45   0     0     0    0                             13    35      0      0    10   0     0     0    0                             14    0       0      0    0    0     0     0    0                             15    0       0      0    0    0     0     0    0                             16    0       0      0    0    0     0     0    0                             17    0       0      0    0    0     0     0    0                             18    0       0      0    18   0     0     0    0                             19    0       0      0    0    22    75    50   0                             20*   --      --     --   --   --    --    --   --                            21    0       0      0    0    0     0     0    0                             22    0       0      0    0    0     0     0    0                             23    0       0      0    0    0     0     0    0                             24    0       20     0    0    0     0     0    0                             25    0       0      0    0    0     0     0    0                             26    0       0      0    0    0     0     0    0                             27    0       0      0    0    0     0     0    0                             28    0       0      0    23   0     0     0    0                             29    0       0      0    20   0     0     0    0                             30    0       0      0    45   0     45    0    0                             31    0       0      0    0    0     0     0    0                             32    0       0      0    0    0     0     0    0                             33    0       0      0    25   0     0     0    0                             34    0       15     35   0    0     0     0    0                             35    0       0      0    0    0     0     0    0                             36    0       0      0    0    0     0     0    0                             37    0       0      0    0    0     0     0    0                             38    60      15     20   63   0     0     0    0                             39    40      0      0    0    0     0     0    0                             40    0       0      0    18   0     0     0    0                             X-1   0       0      0    0    0     0     0    0                             X-2   0       0      0    0    0     0     0    0                             Y-1   0       0      0    0    0     0     0    0                             Y-2   0       0      0    0    0     0     0    0                             Z-1   0       0      0    0    0     0     0    0                             Z-2   0       0      0    0    0     0     0    0                             D-S   55      70     45   50   55    60    10   55                            ______________________________________                                         *Not tested                                                              

As can be seen from Tables 1 and 2, at the dosage tested thecompositions of the present invention exhibited very good pre-emergenceherbicide activity against grasses and in some instances also exhibitedpre-emergence herbicide activity against broad-leaf plants and some postemergence activity. Comparison Compounds X-1 and X-2 (C-3 epimers ofCompounds Nos. 2 and 9 respectively) were inactive as was the CompoundY-1 (the 3-hydroxy analog of Compound 7) and Y-2. Compound D.S.exhibited poor pre-emergence activity against grasses. ComparisonCompounds Z-1 and Z-2 also exhibited pre-emergence activity againstgrasses.

EXAMPLE 18

In this example pre-emergence activity at reduced dosages was determinedfor certain of the compounds of Table A and Comparison Compounds Z-1 andZ-2. This test was conducted in the same manner as the test described inExample 17, hereinabove, except that the test formulations were furtherdiluted to give the dosages indicated in Table 3 hereinbelow. Theresults of this test are summarized in Table 3 hereinbelow.

                                      TABLE 3                                     __________________________________________________________________________    Pre-Emergence Herbicidal Activity                                             Low Dosage Tests                                                                        Broad-Leaf Plants   Grasses                                                   % Phytotoxicity     % Phytotoxicity                                 Compound                                                                            Dosage                                                                            Lambs               Crab                                                                              Water                                                                             Wild                                    No.   γ/cm.sup.2 *                                                                Quarter                                                                            Mustard                                                                            Pigweed                                                                            Soybean                                                                            Grass                                                                             Grass                                                                             Oats                                                                             Rice                                 __________________________________________________________________________    2     11  57   10   20   3    99  100 98 100                                  2     4.4 33   7    0    0    96  100 93 97                                   2     1.8 27   0    0    0    67  99  65 98                                   2     0.7  0   0    0    0    20  87  10 43                                   9     11  43   0    0    2    77  100 53 33                                   9     4.4 25   0    0    0    10  75  13  7                                   9     1.8 13   0    0    0     0  10  0   0                                   9     0.7  0   0    0    0     0   0  0   0                                   Z-1   --  --   --   --   --   --  --  -- --                                   Z-1   4.4  0   0    0    0     0  20  47   0                                  Z-1   1.8  0   0    0    0     0   0  10  0                                   Z-1   0.7  0   0    0    0     0   0  0   0                                   3     11  52   27   23   10   100 100 77 98                                   3     4.4 42   0    0    8    96  99  55 75                                   3     1.8 20   0    0    3    82  99  20 33                                   3     0.7 20   0    0    0    57  99  0  10                                   10    11  43   0    0    7    62  99  0   0                                   10    4.4 33   0    0    0     7  75  0   0                                   10    1.8  0   0    0    0     0  60  0   0                                   10    0.7  0   0    0    0     0  40  0   0                                   Z-2   11  --   --   --   --   --  --  -- --                                   Z-2   4.4  0   0    0    0     0  53  0   0                                   Z-2   1.8  0   0    0    0     0   0  0   0                                   Z-2   .7   0   0    0    0     0   0  0   0                                   4     11  63   0    60   2    100 100 95 100                                  4     4.4 58   0    43   0    98  100 80 100                                  4     1.8 45   0    20   0    73  98  30 62                                   4     0.7  5   0    18   0    33  73  3   8                                   5     11  57   3    27   0    97  100 42 100                                  5     4.4 50   0    23   0    87  98  23 77                                   5     1.8 40   0    13   0    62  87  3  22                                   5     0.7 35   0    3    0     7  68  0   0                                   1     11  43   0    50   0    47  82  0  52                                   1     4.4 33   0    22   0     0  47  0  23                                   1     1.8  0   0    0    0     0   0  0   0                                   1     0.7  0   0    0    0     0   0  0   0                                   8     11   0   0    0    0     0   0  0   0                                   8     4.4  0   0    0    0     0   0  0   0                                   8     1.8  0   0    0    0     0   0  0   0                                   8     0.7  0   0    0    0     0   0  0   0                                   __________________________________________________________________________     *γ/cm.sup.2 = micrograms per square centimeter                     

As can be seen from the results shown in Table 3, the compounds of TableA which were tested at low dosages generally exhibited excellentpre-emergence activity and greatly superior to the activity exhibited byComparison Compounds Z-1 and Z-2.

EXAMPLE 19

In this example pre-emergence activity at reduced dosages weredetermined against an expanded variety of weeds for compound 2 of TableA, hereinabove, of the present invention and3-O-benzyl-6,7-dideoxy-1,2-O-isopropylidene-a-D-xylo-heptofuranos-5-ulose(Formula X-3, wherein R is ##STR13## which is described as a herbicidein commonly assigned application Ser. No. 387,590, filed June 11, 1982,of B. McCaskey.

This test was conducted in the same manner as the test described inExample 17, hereinabove, with the exception of the increased dilution ofthe test compound and the expanded number of plant species. The resultsof this test are summarized in Tables 4-6 hereinbelow.

                                      TABLE 4                                     __________________________________________________________________________    Pre-Emergence Herbicidal Activity                                             Low Dosage Tests                                                                        Grasses                                                                       % Phytotoxicity                                                     Compound                                                                            Dosage                                                                            Crab                                                                              Water                                                                             Wild                                                                             Cheat                                                                             Johnson                                                                            Rye Switch                                                                            Yellow                                                                            Yellow                              No.   γ/cm.sup.2 *                                                                Grass                                                                             Grass                                                                             Oats                                                                             Grass                                                                             Grass                                                                              Grass                                                                             Grass                                                                             Foxtail                                                                           Nutsedge                            __________________________________________________________________________    2     11  99  100 98 --  --   --  --  --  --                                  2     4.4 96  100 93 100 72   100 99  100 62                                  2     1.8 67  99  65 95  48   91  93  90  33                                  2     0.7 20  87  10 47  15   55  37  67   0                                  X-3   11  100 100 97 --  --   --  --  --                                      X-3   4.4 100 100 88 100 72   100 100 100 95                                  X-3   1.8 88  99  85 63   7   93  99  97  53                                  X-3   0.7 70  98  53 38   0   65  43  70  27                                  __________________________________________________________________________     *γ/cm.sup.2 = micrograms per square centimeter                     

                  TABLE 5                                                         ______________________________________                                        Pre-Emergence Herbicidal Activity                                             Low Dosage Tests                                                                        Broad-Leaf Crops                                                    Com-      % Phytotoxicity                                                     pound Dosage  Soy-   Al-  Cot- Pea-      Sugar Toma-                          No.   γ/cm.sup.2 *                                                                    bean   falfa                                                                              ton  nuts Peas Beets toes                           ______________________________________                                        2     11      3      --   --   --   --   --    --                             2     4.4     0      2    0    0    83   57    53                             2     1.8     0      3    0    0    60   32    35                             2     0.7     0      0    0    0    28   15     3                             X-3   11      43     --   --   --   --   --    --                             X-3   4.4     7      23   23   15   72   75    75                             X-3   1.8     0      5    2    0    48   35    48                             X-3   0.7     0      0    0    0    32   20    37                             ______________________________________                                         *γ/cm.sup.2 = micrograms per square centimeter                     

                                      TABLE 6                                     __________________________________________________________________________    Pre-Emergence Herbicidal Activity                                             Low Dosage Tests                                                                        Broad-Leaf Weeds                                                                             Grass Crops                                                    % Phytotoxicity                                                                              % Phytotoxicity                                      Compound                                                                            Dosage                                                                            Lambs                        Wheat                                  No.   γ/cm.sup.2 *                                                                Quarter                                                                            Mustard                                                                            Pigweed                                                                            Rice                                                                             Corn                                                                             Oats                                                                             Sorghum                                                                            Rice                                   __________________________________________________________________________    2     11  57   10   20   100                                                                              -- -- --   --                                     2     4.4 33   7    0    97 89 99 100  98                                     2     1.8 27   0    0    98 67 90 53   97                                     2     0.7  0   0    0    43 43 73 10   17                                     X-3   11  62   47   33   100                                                                              -- -- --   --                                     X-3   4.4 50   12   23   90 97 99 100  100                                    X-3   1.8 37   3    0    63 70 85 70   92                                     X-3   0.7 27   0    0    13 35 72 33   63                                     __________________________________________________________________________     *γ/cm.sup.2 = micrograms per square centimeter                     

As can be seen from Tables 4-6, both compounds exhibit exceptionalpre-emergence grass herbicidal activity at reduced dosages and inaddition, compound 2 exhibits excellent safety for use with soybean,alfalfa, cotton and peanut crops.

Obviously, many modifications and variations of the invention describedhereinabove and below in the claims can be made without departing fromthe essence and scope thereof.

What is claimed is:
 1. A compound having the formula: ##STR14## whereinR is lower alkyl having 1 through 4 carbon atoms or alkenyl having 2through 4 carbon atoms;R¹ is 2-trifluoromethylphenyl, aryl having 6through 10 carbon atoms or substituted aryl having 1 through 4substituents independently selected from the group of lower alkyl having1 through 4 carbon atoms, lower alkoxy having 1 through 4 carbon atoms,and halo, with the proviso that when R¹ is substituted aryl having morethan two halo substituents or is 2,3- or 2,4-dihalophenyl, then R isalkyl; and R² and R³ are independently hydrogen or lower alkyl with theproviso that when R is methyl, butyl, vinyl, 2-allyl or but-1-enyl, andR² and R³ are each methyl, then R¹ is not phenyl.
 2. The compound ofclaim 1 wherein R¹ is aryl or monosubstituted aryl having a solesubstituent selected from the group of lower alkyl, lower alkoxy, andhalo.
 3. The compound of claim 2 wherein R¹ is phenyl or monosubstitutedphenyl having its sole substituent at the 2 position.
 4. The compound ofclaim 3 wherein R is lower alkyl.
 5. The compound of claim 4 wherein Ris ethyl or propyl and R¹ is phenyl, 2-chlorophenyl, or 2-fluorophenylor 2-methylphenyl.
 6. The compound of claim 5 wherein R² and R³ are eachmethyl.
 7. The compound of claim 1 wherein R is lower alkyl.
 8. Thecompound of claim 7 wherein R is ethyl or propyl.
 9. The compound ofclaim 1 wherein R is alkenyl having 2 through 4 carbon atoms.
 10. Thecompound of claim 9 wherein R² and R³ are each methyl and R¹ is phenyl,2-chlorophenyl, 2-fluorophenyl or 2-methylphenyl.
 11. The compound ofclaim 1 wherein R² and R³ are each methyl.
 12. The compound of claim 11wherein R is ethyl and R¹ is phenyl.
 13. The compound of claim 11wherein R is ethyl and R¹ is 2-chlorophenyl.
 14. The compound of claim11 wherein R is ethyl and R¹ is 2-fluorophenyl.
 15. The compound ofclaim 11 wherein R is ethyl and R¹ is 2-methylphenyl.